问题

Complete the square for the following quadratic: $5 x^2-8 x-16$. Please put your final answer in a $\\boxed{}$.

答案

模型 模型答案 正确答案
金声玉亮2.0 To complete the square for the quadratic expression \(5x^2 - 8x - 16\), follow these steps:

1. **Factor out the coefficient of \(x^2\) from the first two terms:**
\[
5(x^2 - \frac{8}{5}x) - 16
\]

2. **Complete the square inside the parentheses:**
- Take the coefficient of \(x\), which is \(-\frac{8}{5}\), divide it by 2, and square it:
\[
\left(\frac{-\frac{8}{5}}{2}\right)^2 = \left(\frac{-8}{10}\right)^2 = \left(\frac{-4}{5}\right)^2 = \frac{16}{25}
\]
- Add and subtract this square inside the parentheses:
\[
5\left(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}\right) - 16
\]
- Simplify the expression inside the parentheses:
\[
5\left(\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right) - 16
\]

3. **Distribute the 5 and simplify:**
\[
5\left(x - \frac{4}{5}\right)^2 - 5 \cdot \frac{16}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5} - \frac{80}{5}
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

4. **Write the final completed square form:**
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Thus, the completed square form of the quadratic expression \(5x^2 - 8x - 16\) is:
\[
\boxed{5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}}
\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
deepseek-r1

To complete the square for the quadratic \(5x^2 - 8x - 16\):

1. Factor out the coefficient of \(x^2\) from the first two terms:
\[
5(x^2 - \frac{8}{5}x) - 16
\]

2. To complete the square inside the parentheses, take half of the coefficient of \(x\), which is \(-\frac{4}{5}\), and square it to get \(\left(-\frac{4}{5}\right)^2 = \frac{16}{25}\). Add and subtract this value inside the parentheses:
\[
5\left(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}\right) - 16
\]

3. Simplify the expression by factoring the perfect square trinomial and adjusting the constants:
\[
5\left(\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right) - 16
\]

4. Distribute the 5 and combine the constants:
\[
5\left(x - \frac{4}{5}\right)^2 - 5 \cdot \frac{16}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5} - \frac{80}{5}
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Thus, the quadratic \(5x^2 - 8x - 16\) in completed square form is \(\boxed{5\left(x - \dfrac{4}{5}\right)^2 - \dfrac{96}{5}}\).
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
gpto1 To complete the square for the quadratic expression \(5x^2 - 8x - 16\), we proceed step by step:

**Step 1:** Factor out the coefficient of \(x^2\) from the \(x^2\) and \(x\) terms:
\[
5x^2 - 8x - 16 = 5\left(x^2 - \frac{8}{5}x\right) - 16
\]

**Step 2:** Complete the square inside the parentheses. Take half of the coefficient of \(x\) (which is \(-\frac{8}{5}\)):
\[
\frac{1}{2} \times \left(-\frac{8}{5}\right) = -\frac{4}{5}
\]
Square this value:
\[
\left(-\frac{4}{5}\right)^2 = \frac{16}{25}
\]
Add and subtract this square inside the parentheses:
\[
5\left[\left(x^2 - \frac{8}{5}x + \frac{16}{25}\right) - \frac{16}{25}\right] - 16
\]

**Step 3:** Simplify the expression. The quadratic inside the parentheses is now a perfect square:
\[
5\left[\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right] - 16
\]

**Step 4:** Distribute the 5 and combine constants:
\[
5\left(x - \frac{4}{5}\right)^2 - 5 \times \frac{16}{25} - 16 = 5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5} - 16
\]
\[
\text{Since } -\frac{16}{5} - 16 = -\frac{16}{5} - \frac{80}{5} = -\frac{96}{5}
\]

**Final Answer:**
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Answer: \boxed{5\left( x\!-\!\dfrac{4}{5} \right)^{2}\ -\ \dfrac{96}{5}}
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
gpt-4o-2024-08-06 To complete the square for the quadratic expression \(5x^2 - 8x - 16\), we follow these steps:

1. **Factor out the coefficient of \(x^2\) from the first two terms:**

The coefficient of \(x^2\) is 5. We factor 5 out of the terms involving \(x\):

\[
5x^2 - 8x = 5(x^2 - \frac{8}{5}x)
\]

2. **Complete the square inside the parentheses:**

To complete the square for the expression \(x^2 - \frac{8}{5}x\), we need to find a constant that makes it a perfect square trinomial. The formula for completing the square is:

\[
x^2 + bx \rightarrow \left(x + \frac{b}{2}\right)^2 - \left(\frac{b}{2}\right)^2
\]

Here, \(b = -\frac{8}{5}\). Calculate \(\frac{b}{2}\):

\[
\frac{-\frac{8}{5}}{2} = -\frac{4}{5}
\]

Now, square \(-\frac{4}{5}\):

\[
\left(-\frac{4}{5}\right)^2 = \frac{16}{25}
\]

Add and subtract \(\frac{16}{25}\) inside the parentheses:

\[
x^2 - \frac{8}{5}x = \left(x - \frac{4}{5}\right)^2 - \frac{16}{25}
\]

3. **Substitute back into the expression:**

Substitute the completed square back into the expression:

\[
5(x^2 - \frac{8}{5}x) = 5\left(\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right)
\]

Distribute the 5:

\[
5\left(x - \frac{4}{5}\right)^2 - 5 \cdot \frac{16}{25} = 5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5}
\]

4. **Combine with the constant term:**

The original expression is \(5x^2 - 8x - 16\). We now combine \(-\frac{16}{5}\) with \(-16\):

Convert \(-16\) to a fraction with a denominator of 5:

\[
-16 = -\frac{80}{5}
\]

Combine the constants:

\[
-\frac{16}{5} - \frac{80}{5} = -\frac{96}{5}
\]

5. **Write the final expression:**

The completed square form of the quadratic is:

\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Therefore, the completed square form of the quadratic expression is:

\[
\boxed{5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}}
\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
DeepSeek-Coder-V2-Lite-Instruct To complete the square for the quadratic expression \(5x^2 - 8x - 16\), we follow these steps:

1. **Factor out the coefficient of \(x^2\) from the first two terms:**
\[
5x^2 - 8x - 16 = 5(x^2 - \frac{8}{5}x) - 16
\]

2. **Complete the square inside the parentheses:**
- Take the coefficient of \(x\) inside the parentheses, which is \(-\frac{8}{5}\).
- Divide it by 2: \(\frac{-\frac{8}{5}}{2} = -\frac{4}{5}\).
- Square this result: \(\left(-\frac{4}{5}\right)^2 = \frac{16}{25}\).

3. **Add and subtract this square inside the parentheses:**
\[
5\left(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}\right) - 16
\]
\[
= 5\left(\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right) - 16
\]

4. **Distribute the 5 and simplify:**
\[
= 5\left(x - \frac{4}{5}\right)^2 - 5 \cdot \frac{16}{25} - 16
\]
\[
= 5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - 16
\]
\[
= 5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - \frac{400}{25}
\]
\[
= 5\left(x - \frac{4}{5}\right)^2 - \frac{480}{25}
\]
\[
= 5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Thus, the completed square form of the quadratic expression \(5x^2 - 8x - 16\) is:
\[
\boxed{5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}}
\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
Meta-Llama-3.1-405B-Instruct-Turbo ## Step 1: Identify the quadratic equation
The given quadratic equation is $5x^2 - 8x - 16$.

## Step 2: Divide the entire equation by the coefficient of $x^2$ to make the coefficient of $x^2$ equal to 1
Dividing the entire equation by 5 gives $x^2 - \frac{8}{5}x - \frac{16}{5}$.

## Step 3: Move the constant term to the right side of the equation
Moving the constant term gives $x^2 - \frac{8}{5}x = \frac{16}{5}$.

## Step 4: Take half of the coefficient of $x$, square it, and add it to both sides of the equation
Half of the coefficient of $x$ is $-\frac{4}{5}$. Squaring it gives $\frac{16}{25}$. Adding it to both sides gives $x^2 - \frac{8}{5}x + \frac{16}{25} = \frac{16}{5} + \frac{16}{25}$.

## Step 5: Simplify the right side of the equation
Simplifying the right side gives $x^2 - \frac{8}{5}x + \frac{16}{25} = \frac{80}{25} + \frac{16}{25}$, which simplifies to $x^2 - \frac{8}{5}x + \frac{16}{25} = \frac{96}{25}$.

## Step 6: Factor the left side of the equation into a perfect square
Factoring the left side gives $\left(x - \frac{4}{5}\right)^2 = \frac{96}{25}$.

## Step 7: Write the final answer in the required format
The final answer is: $\boxed{\left(x - \frac{4}{5}\right)^2 = \frac{96}{25}}$
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
Meta-Llama-3.1-70B-Instruct-Turbo ## Step 1: Identify the coefficients of the quadratic equation
The given quadratic equation is $5x^2 - 8x - 16$. The coefficients are $a = 5$, $b = -8$, and $c = -16$.

## Step 2: Factor out the coefficient of $x^2$ from the first two terms
To complete the square, we first factor out the coefficient of $x^2$, which is $5$, from the first two terms: $5x^2 - 8x = 5(x^2 - \frac{8}{5}x)$.

## Step 3: Find the value to complete the square
To complete the square, we need to add and subtract $(\frac{b}{2})^2$ inside the parentheses. In this case, $\frac{b}{2} = \frac{-8}{2 \cdot 5} = -\frac{4}{5}$. So, $(\frac{b}{2})^2 = (-\frac{4}{5})^2 = \frac{16}{25}$.

## Step 4: Add and subtract the value to complete the square
We add and subtract $\frac{16}{25}$ inside the parentheses: $5(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25})$.

## Step 5: Write the expression as a perfect square and simplify
Now, we can write the expression as a perfect square: $5(x^2 - \frac{8}{5}x + \frac{16}{25}) - 5 \cdot \frac{16}{25} - 16$. This simplifies to $5(x - \frac{4}{5})^2 - \frac{80}{25} - 16$.

## Step 6: Simplify the constant terms
Combine the constant terms: $-\frac{80}{25} - 16 = -\frac{80}{25} - \frac{400}{25} = -\frac{480}{25} = -\frac{96}{5}$.

## Step 7: Write the final expression in completed square form
The final expression in completed square form is $5(x - \frac{4}{5})^2 - \frac{96}{5}$.

The final answer is: $\boxed{5(x - \frac{4}{5})^2 - \frac{96}{5}}$
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
Qwen2-72B-Instruct To complete the square for the quadratic expression $5x^2 - 8x - 16$, we first factor out the coefficient of $x^2$ from the first two terms:

\[5x^2 - 8x - 16 = 5(x^2 - \frac{8}{5}x) - 16\]

Next, we find the value that completes the square for the expression inside the parentheses. This is done by taking half of the coefficient of $x$ (which is $\frac{8}{5}$), squaring it, and adding it inside the parentheses. Half of $\frac{8}{5}$ is $\frac{4}{5}$, and squaring this gives $\left(\frac{4}{5}\right)^2 = \frac{16}{25}$. We add and subtract this value inside the parentheses to maintain equality:

\[= 5\left(x^2 - \frac{8}{5}x + \left(\frac{4}{5}\right)^2 - \left(\frac{4}{5}\right)^2\right) - 16\]

\[= 5\left[\left(x - \frac{4}{5}\right)^2 - \left(\frac{4}{5}\right)^2\right] - 16\]

\[= 5\left(x - \frac{4}{5}\right)^2 - 5\left(\frac{16}{25}\right) - 16\]

\[= 5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - 16\]

\[= 5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - \frac{400}{25}\]

\[= 5\left(x - \frac{4}{5}\right)^2 - \frac{480}{25}\]

\[= 5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}\]

Therefore, the completed square form of $5x^2 - 8x - 16$ is:

\[\boxed{5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}}\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
baichuan4 To complete the square for the quadratic $5x^2 - 8x - 16$, we first need to identify the coefficients of the quadratic terms and the linear term. The coefficient of the quadratic term is $5$, and the coefficient of the linear term is $-8$.

Our goal is to rewrite the quadratic in the form $(ax + b)^2 + c$, where $a$, $b$, and $c$ are constants. To do this, we need to ensure that the $x^2$ and $x$ terms in the expanded form of $(ax + b)^2$ match the corresponding terms in the original quadratic.

The expanded form of $(ax + b)^2$ is $a^2x^2 + 2abx + b^2$. We want the coefficient of $x^2$ in this expansion to match the coefficient of $x^2$ in the original quadratic, which is $5$. Therefore, we need $a^2 = 5$, so $a = \sqrt{5}$.

Next, we want the coefficient of $x$ in the expansion to match the coefficient of $x$ in the original quadratic, which is $-8$. In the expansion, the coefficient of $x$ is $2ab$. We have $a = \sqrt{5}$, so we need $2ab = -8$. Solving for $b$, we get $b = \frac{-8}{2\sqrt{5}} = \frac{-4}{\sqrt{5}}$.

Now we can write the quadratic in the form $(ax + b)^2 + c$. We have $a = \sqrt{5}$ and $b = \frac{-4}{\sqrt{5}}$, so the square part is $(\sqrt{5}x - \frac{4}{\sqrt{5}})^2$.

To find $c$, we need to calculate the constant term in the expanded form of $(\sqrt{5}x - \frac{4}{\sqrt{5}})^2$ and compare it to the constant term in the original quadratic, which is $-16$.

Expanding $(\sqrt{5}x - \frac{4}{\sqrt{5}})^2$, we get:
$$
(\sqrt{5}x - \frac{4}{\sqrt{5}})^2 = (\sqrt{5}x)^2 - 2(\sqrt{5}x)(\frac{4}{\sqrt{5}}) + (\frac{4}{\sqrt{5}})^2
$$
$$
= 5x^2 - 8x + \frac{16}{5}
$$

Comparing this to the original quadratic $5x^2 - 8x - 16$, we see that the constant term in the expanded square is $\frac{16}{5}$, while the constant term in the original quadratic is $-16$. Therefore, $c = -16 - \frac{16}{5} = -\frac{80}{5} - \frac{16}{5} = -\frac{96}{5}$.

Putting it all together, we can write the original quadratic as:
$$
5x^2 - 8x - 16 = (\sqrt{5}x - \frac{4}{\sqrt{5}})^2 - \frac{96}{5}
$$

However, we want to express $c$ in the form $k - \frac{16}{5}$ for some constant $k$. We have $c = -\frac{96}{5}$, so $k = -\frac{96}{5} + \frac{16}{5} = -\frac{80}{5} = -16$.

Therefore, the final answer is:
$$
5x^2 - 8x - 16 = (\sqrt{5}x - \frac{4}{\sqrt{5}})^2 - 16
$$

We can check our answer by expanding the square and verifying that the resulting expression matches the original quadratic.
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
doubao $5x^2 - 8x - 16$
$5(x^2 - \frac{8}{5}x) - 16$
$5(x^2 - \frac{8}{5}x + (\frac{8}{5}\div2)^2 - (\frac{8}{5}\div2)^2) - 16$
$5(x^2 - \frac{8}{5}x + (\frac{4}{5})^2 - (\frac{4}{5})^2) - 16$
$5((x - \frac{4}{5})^2 - \frac{16}{25}) - 16$
$5(x - \frac{4}{5})^2 - 5\times\frac{16}{25} - 16$
$5(x - \frac{4}{5})^2 - \frac{16}{5} - 16$
$5(x - \frac{4}{5})^2 - \frac{16}{5} - \frac{80}{5}$
$5(x - \frac{4}{5})^2 - \frac{96}{5}$
$\boxed{5(x - \frac{4}{5})^2 - \frac{96}{5}}$
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
gpto1 To complete the square for the quadratic expression \(5x^2 - 8x - 16\), we proceed step by step:

**Step 1:** Factor out the coefficient of \(x^2\) from the \(x^2\) and \(x\) terms:
\[
5x^2 - 8x - 16 = 5\left(x^2 - \frac{8}{5}x\right) - 16
\]

**Step 2:** Complete the square inside the parentheses. Take half of the coefficient of \(x\) (which is \(-\frac{8}{5}\)):
\[
\frac{1}{2} \times \left(-\frac{8}{5}\right) = -\frac{4}{5}
\]
Square this value:
\[
\left(-\frac{4}{5}\right)^2 = \frac{16}{25}
\]
Add and subtract this square inside the parentheses:
\[
5\left[\left(x^2 - \frac{8}{5}x + \frac{16}{25}\right) - \frac{16}{25}\right] - 16
\]

**Step 3:** Simplify the expression. The quadratic inside the parentheses is now a perfect square:
\[
5\left[\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right] - 16
\]

**Step 4:** Distribute the 5 and combine constants:
\[
5\left(x - \frac{4}{5}\right)^2 - 5 \times \frac{16}{25} - 16 = 5\left(x - \frac{4}{5}\right)^2 - \frac{16}{5} - 16
\]
\[
\text{Since } -\frac{16}{5} - 16 = -\frac{16}{5} - \frac{80}{5} = -\frac{96}{5}
\]

**Final Answer:**
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{96}{5}
\]

Answer: \boxed{5\left( x\!-\!\dfrac{4}{5} \right)^{2}\ -\ \dfrac{96}{5}}
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
kimi To complete the square for the quadratic expression \(5x^2 - 8x - 16\), we will follow these steps:

1. **Factor out the coefficient of \(x^2\) from the first two terms:**
\[
5x^2 - 8x - 16 = 5(x^2 - \frac{8}{5}x) - 16
\]

2. **Identify the coefficient of \(x\) inside the parentheses, which is \(-\frac{8}{5}\). To complete the square, we need to add and subtract the square of half of this coefficient:**
\[
\left(\frac{-\frac{8}{5}}{2}\right)^2 = \left(-\frac{4}{5}\right)^2 = \frac{16}{25}
\]

3. **Add and subtract \(\frac{16}{25}\) inside the parentheses:**
\[
5\left(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}\right) - 16
\]

4. **Rewrite the expression inside the parentheses as a perfect square trinomial and a constant term:**
\[
5\left((x - \frac{4}{5})^2 - \frac{16}{25}\right) - 16
\]

5. **Distribute the 5 through the parentheses:**
\[
5(x - \frac{4}{5})^2 - 5 \cdot \frac{16}{25} - 16
\]

6. **Simplify the constant terms:**
\[
5(x - \frac{4}{5})^2 - \frac{80}{25} - 16
\]
\[
5(x - \frac{4}{5})^2 - \frac{80}{25} - \frac{400}{25}
\]
\[
5(x - \frac{4}{5})^2 - \frac{480}{25}
\]
\[
5(x - \frac{4}{5})^2 - \frac{96}{5}
\]

Thus, the completed square form of the quadratic expression \(5x^2 - 8x - 16\) is:
\[
\boxed{5(x - \frac{4}{5})^2 - \frac{96}{5}}
\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
minimax To complete the square for the quadratic equation $5x^2 - 8x - 16$, we need to form a perfect square trinomial from the first two terms. Here are the steps:

1. Factor out the coefficient of $x^2$ from the first two terms:
$$ 5(x^2 - \frac{8}{5}x) - 16 $$

2. Find the value that completes the square for the expression in the parentheses. This value is $(\frac{b}{2a})^2$, where $a$ is the coefficient of $x^2$ (which is 1 after factoring out the 5) and $b$ is the coefficient of $x$ (which is $-\frac{8}{5}$ in this case). So we calculate:
$$ \left(\frac{-\frac{8}{5}}{2 \cdot 1}\right)^2 = \left(\frac{-8}{10}\right)^2 = \left(\frac{-4}{5}\right)^2 = \frac{16}{25} $$

3. Add and subtract this value inside the parentheses to complete the square:
$$ 5\left(x^2 -
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
wenxinyiyan 首先,我们需要将二次项系数化为1,这样我们就可以更轻松地完成平方。我们可以通过将整个表达式除以5来实现这一点:
$5x^2 - 8x - 16 = 5(x^2 - \frac{8}{5}x) - 16$
接下来,我们需要找到一个数,使得$x^2 - \frac{8}{5}x$可以变成一个完全平方。这个数应该是线性项系数的一半的平方,即$(\frac{8}{10})^2 = \frac{16}{25}$。
然后,我们将这个数加到表达式中并减去相同的数,以保持等式的平衡:
$5(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}) - 16$
现在我们可以完成平方了:
$5((x - \frac{4}{5})^2 - \frac{16}{25}) - 16$
最后,我们可以将常数项合并,得到最终答案:
$\boxed{5(x - \frac{4}{5})^2 - \frac{104}{5}}$
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
zhipu To complete the square for the quadratic $5x^2 - 8x - 16$, follow these steps:

1. **Factor out the leading coefficient** from the terms involving $x$:
\[
5x^2 - 8x - 16 = 5(x^2 - \frac{8}{5}x) - 16
\]

2. **Complete the square** inside the parentheses:
- Take half of the coefficient of $x$, square it, and add and subtract it inside the parentheses:
\[
\left(\frac{-\frac{8}{5}}{2}\right)^2 = \left(-\frac{4}{5}\right)^2 = \frac{16}{25}
\]
- Add and subtract this square inside the parentheses:
\[
5\left(x^2 - \frac{8}{5}x + \frac{16}{25} - \frac{16}{25}\right) - 16
\]
- Simplify the expression inside the parentheses:
\[
5\left(\left(x - \frac{4}{5}\right)^2 - \frac{16}{25}\right) - 16
\]

3. **Distribute the 5** and combine the constants:
\[
5\left(x - \frac{4}{5}\right)^2 - 5 \cdot \frac{16}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - \frac{80}{25} - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - 3.2 - 16
\]
\[
5\left(x - \frac{4}{5}\right)^2 - 19.2
\]

Thus, the completed square form of the quadratic $5x^2 - 8x - 16$ is:
\[
\boxed{5\left(x - \frac{4}{5}\right)^2 - 19.2}
\]
5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}
deepseek-v3 Error code: 400 - {'error': {'code': 'RequestTimeOut', 'param': None, 'message': 'Request timed out, please try again later.', 'type': 'RequestTimeOut'}, 'id': 'chatcmpl-9b57063a-84e9-98f4-b6fd-f6d517167b64', 'request_id': '9b57063a-84e9-98f4-b6fd-f6d517167b64'} 5 \left(x-\frac{4}{5}\right)^2-\frac{96}{5}