问题


There is a single choice question about high school mathematics. Answer the question by replying A, B, C or D.
Question: (i + 1)(5 – 5i)(5 + 5i) =
A. 50 + 50i
B. 50 – 50i
C. 25 + 25i
D. 25 – 25i
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

A. 50 + 50i

Explanation:

(i + 1)(5 – 5i)(5 + 5i) = (i + 1)(25 + 25) = (i + 1)(50) = 50i + 50 = 50 + 50i.
A
deepseekr1

The given expression is (i + 1)(5 – 5i)(5 + 5i). First, recognize that (5 – 5i) and (5 + 5i) are conjugates. Multiplying them:
\[
(5 - 5i)(5 + 5i) = 5^2 - (5i)^2 = 25 - (-25) = 50.
\]
Now, the expression simplifies to:
\[
(i + 1) \cdot 50 = 50(i + 1) = 50i + 50 = 50 + 50i.
\]
The result matches **A. 50 + 50i**.

**Answer:** A
A
gpto1 A A
GPT-4o To solve the question, we need to simplify the expression \((i + 1)(5 - 5i)(5 + 5i)\).

First, let's simplify \((5 - 5i)(5 + 5i)\):

\[
(5 - 5i)(5 + 5i) = 5^2 - (5i)^2 = 25 - 25i^2
\]

Since \(i^2 = -1\):

\[
25 - 25(-1) = 25 + 25 = 50
\]

So, \((5 - 5i)(5 + 5i) = 50\).

Next, we multiply this result by \((i + 1)\):

\[
(i + 1) \cdot 50 = 50i + 50
\]

So, the expression \((i + 1)(5 - 5i)(5 + 5i)\) simplifies to \(50 + 50i\).

Therefore, the answer is:
\[
A. 50 + 50i
\]
A
llama3.1-70B-Instruct

(i + 1)(5 – 5i)(5 + 5i)
= (i + 1)(25 – 25i2)
= (i + 1)(25 + 25)
= (i + 1)(50)
= 50 + 50i
A
llama3.1-405B-Instruct

A
A
DeepSeek-Coder-V2 To solve the given expression \((i + 1)(5 - 5i)(5 + 5i)\), we will follow these steps:

1. **Simplify the product of the complex conjugates:**
\[
(5 - 5i)(5 + 5i)
\]
Using the difference of squares formula \( (a - bi)(a + bi) = a^2 + b^2 \):
\[
(5 - 5i)(5 + 5i) = 5^2 + (5i)^2 = 25 + 25(-1) = 25 - 25 = 25
\]

2. **Multiply the result by \((i + 1)\):**
\[
(i + 1) \cdot 25
\]
Distribute the 25:
\[
25(i + 1) = 25i + 25
\]

Thus, the final expression is:
\[
25i + 25
\]

Comparing this with the given options, the correct answer is:
\[
\boxed{C}
\]
A
Qwen2-72B-Instruct B. 50 – 50i A
baichuan4 B A
doubao B.

First, calculate (5 - 5i)(5 + 5i) = 5^2 - (5i)^2 = 25 - 25i^2 = 25 - 25(-1) = 25 + 25 = 50.

Then multiply by (i + 1): 50(i + 1) = 50i + 50 = 50 - 50i.
A
minimax To solve the given expression, we can use the difference of squares formula, which states that (a - b)(a + b) = a^2 - b^2. Here, we can consider (5 - 5i) and (5 + 5i) as a pair that fits the difference of squares formula, where a = 5 and b = 5i.

So, (5 - 5i)(5 + 5i) = 5^2 - (5i)^2 = 25 - 25(-1) = 25 + 25 = 50.

Now, we multiply this result by (i + 1):

(i + 1)(50) = 50i + 50.

Therefore, the correct answer is:

A. 50 + 50i
A
kimi To solve this problem, we can use the difference of squares formula, which states that \((a - b)(a + b) = a^2 - b^2\). Here, \(a = 5\) and \(b = 5i\), so we can simplify the expression \((5 - 5i)(5 + 5i)\) as follows:

\[
(5 - 5i)(5 + 5i) = 5^2 - (5i)^2 = 25 - 25i^2
\]

Since \(i^2 = -1\), we can substitute that in:

\[
25 - 25(-1) = 25 + 25 = 50
\]

Now, we multiply this result by \(i + 1\):

\[
(i + 1)(50) = 50i + 50
\]

So the final answer is:

\[
50 + 50i
\]

Therefore, the correct answer is \(\boxed{\text{A}}\).
A
wenxinyiyan B

Explanation:
To solve this problem, we need to multiply the given complex numbers. Let's do it step by step.

Step 1: Multiply the first two complex numbers.
(i + 1)(5 – 5i) = i(5) + i(-5i) + 1(5) + 1(-5i)
= 5i - 5i^2 + 5 - 5i
Since i^2 = -1, we can simplify the expression as:
= 5i + 5 + 5 - 5i
= 10 + 5i (This is the intermediate result)

Step 2: Multiply the intermediate result with the third complex number.
(10 + 5i)(5 + 5i) = 10(5) + 10(5i) + 5i(5) + 5i(5i)
= 50 + 50i + 25i + 25i^2
Again, using i^2 = -1, we get:
= 50 + 50i + 25i - 25
= 25 + 75i (This is the intermediate result)

Oops! It seems like I made a mistake in Step 1. Let's correct it and redo the calculations.

Step 1 (Corrected): Multiply the first two complex numbers.
(i + 1)(5 – 5i) = i(5) + i(-5i) + 1(5) + 1(-5i)
= 5i - 5i^2 + 5 - 5i
Since i^2 = -1, we can simplify the expression as:
= 5i + 5 + 5 - 5i
= 10 (Corrected intermediate result)

Step 2 (Redo): Multiply the corrected intermediate result with the third complex number.
10(5 + 5i) = 10(5) + 10(5i)
= 50 + 50i

However, we can further simplify this by multiplying it with the conjugate of the second complex number's denominator, which is actually (5 - 5i) in this case, but since we already multiplied it, we just need to multiply by the last part (5 + 5i). This will give us:

10(5 + 5i) / (5 + 5i)(5 - 5i) (We multiply by the conjugate to eliminate the imaginary part in the denominator)
= 10(5 + 5i) / (25 - 25i^2)
= 10(5 + 5i) / (25 + 25) (Since i^2 = -1)
= 10(5 + 5i) / 50
= (5 + 5i) / 5
= 1 + i (This is the corrected intermediate result after dividing)

Now, let's multiply this by the original first complex number (i + 1):

(i + 1)(1 + i) = i(1) + i(i) + 1(1) + 1(i)
= i + i^2 + 1 + i
= i - 1 + 1 + i (Since i^2 = -1)
= 2i (This is the final corrected intermediate result)

Now, we multiply this by 50 (the result of multiplying the denominators):

2i * 50 = 100i

Wait, this is still not correct. It seems like we went off track. Let's go back to the original expression and solve it in a different way.

(i + 1)(5 – 5i)(5 + 5i)

First, let's use the fact that (a - b)(a + b) = a^2 - b^2 to simplify the last two factors:

(5 - 5i)(5 + 5i) = 5^2 - (5i)^2
= 25 - 25i^2
= 25 + 25 (Since i^2 = -1)
= 50

Now, we multiply this by the first factor (i + 1):

(i + 1) * 50 = 50i + 50

However, this is still not one of the options. It seems like there might be a typo in the question or the options
A
zhipu To solve the expression \((i + 1)(5 - 5i)(5 + 5i)\), let's break it down step by step.

First, consider the product \((5 - 5i)(5 + 5i)\). This is a difference of squares:
\[
(5 - 5i)(5 + 5i) = 5^2 - (5i)^2
\]

We know that \(5^2 = 25\) and \((5i)^2 = 25i^2\). Since \(i^2 = -1\), we have:
\[
(5i)^2 = 25(-1) = -25
\]

So, the expression simplifies to:
\[
5^2 - (5i)^2 = 25 - (-25) = 25 + 25 = 50
\]

Now, we need to multiply this result by \((i + 1)\):
\[
(i + 1) \cdot 50
\]

Distribute 50:
\[
50i + 50
\]

So, the final result is:
\[
50 + 50i
\]

Therefore, the correct answer is:
A. 50 + 50i
A
gpto1 A A
deepseekv3 To solve the expression \((i + 1)(5 - 5i)(5 + 5i)\), we proceed step by step.

1. **Simplify \((5 - 5i)(5 + 5i)\)**:
This is a product of a complex number and its conjugate, so we use the formula \((a - bi)(a + bi) = a^2 + b^2\):
\[
(5 - 5i)(5 + 5i) = 5^2 + 5^2 = 25 + 25 = 50.
\]

2. **Multiply the result by \((i + 1)\)**:
Now we have:
\[
(i + 1) \cdot 50 = 50i + 50.
\]

3. **Rearrange the terms**:
\[
50i + 50 = 50 + 50i.
\]

Thus, the correct answer is:

**A. 50 + 50i**
A