问题


There is a single choice question about high school mathematics. Answer the question by replying A, B, C or D.
Question: Let $p$, $q$, and $r$ be constants. One solution to the equation $(x-p)(x-q) = (r-p)(r-q)$ is $x=r$. Find the other solution in terms of $p$, $q$, and $r$.
A. pqr
B. pq-r
C. p-q-r
D. p+q-r
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

D
D
deepseekr1

The equation \((x - p)(x - q) = (r - p)(r - q)\) is given, with \(x = r\) as one solution. To find the other solution, expand both sides:

- Left side: \((x - p)(x - q) = x^2 - (p + q)x + pq\)
- Right side: \((r - p)(r - q) = r^2 - (p + q)r + pq\)

Subtracting the right side from the left gives:
\[
x^2 - (p + q)x + pq - \left[r^2 - (p + q)r + pq\right] = 0 \implies x^2 - (p + q)x - r^2 + (p + q)r = 0
\]

Since \(x = r\) is a root, factor \((x - r)\) out. Let the other root be \(s\). For a quadratic \(x^2 - (p + q)x + \text{constant}\), the sum of roots is \(p + q\). Therefore:
\[
r + s = p + q \implies s = p + q - r
\]

Alternatively, substituting \(y = x - r\) simplifies the equation to \(y(y + (r - p) + (r - q)) = 0\), leading to \(x = r + y = p + q - r\).

**Answer:** D. \(p + q - r\)
D
gpto1 D D
GPT-4o To find the other solution for the equation \((x-p)(x-q) = (r-p)(r-q)\), we start by noting that \(x = r\) is one of the solutions. We can rewrite the equation and solve for the other solution.

Given:
\[
(x-p)(x-q) = (r-p)(r-q)
\]

First, let's expand both sides:
\[
x^2 - (p+q)x + pq = r^2 - (p+q)r + pq
\]

Next, we can see that the term \(pq\) cancels out on both sides:
\[
x^2 - (p+q)x = r^2 - (p+q)r
\]

Rearrange the equation:
\[
x^2 - (p+q)x - r^2 + (p+q)r = 0
\]

Combine like terms:
\[
x^2 - (p+q)x + (p+q)r - r^2 = 0
\]

This is a quadratic equation in the form:
\[
x^2 - (p+q)x + (p+q)r - r^2 = 0
\]

We know one solution is \(x = r\). Let \(x = a\) be the other solution. We can use the fact that the sum of the solutions of a quadratic equation \(ax^2 + bx + c = 0\) is given by \(-\frac{b}{a}\). For our equation:
\[
x^2 - (p+q)x + [(p+q)r - r^2] = 0
\]

Here, \(a = 1\), \(b = -(p+q)\), and \(c = (p+q)r - r^2\).

The sum of the solutions \(r + a\) is:
\[
r + a = p + q
\]

Therefore:
\[
a = (p + q) - r
\]

Thus, the other solution in terms of \(p\), \(q\), and \(r\) is:
\[
\boxed{p + q - r}
\]
D
llama3.1-70B-Instruct

D
The best answer is D.
D
llama3.1-405B-Instruct

D
D
DeepSeek-Coder-V2 D. p+q-r D
Qwen2-72B-Instruct D. p+q-r D
baichuan4 D D
doubao Expand the left side of the equation: $(x-p)(x-q)=x^2-qx-px+pq=x^2-(p+q)x+pq$.
Expand the right side of the equation: $(r-p)(r-q)=r^2-qr-pr+pq=r^2-(p+q)r+pq$.
So the equation becomes $x^2-(p+q)x+pq=r^2-(p+q)r+pq$.
Subtracting $pq$ from both sides gives $x^2-(p+q)x=r^2-(p+q)r$.
Subtracting $r^2-(p+q)r$ from both sides gives $x^2-(p+q)x-r^2+(p+q)r=0$.
Factor the left side: $(x-r)(x+r-p-q)=0$.
So the other solution is $x=p+q-r$.
So the answer is D.
D
minimax To find the other solution to the equation $(x-p)(x-q) = (r-p)(r-q)$, we can first expand both sides of the equation:

On the left side:
$(x-p)(x-q) = x^2 - qx - px + pq = x^2 - (p+q)x + pq$

On the right side:
$(r-p)(r-q) = r^2 - qr - pr + pq = r^2 - (p+q)r + pq$

Since we know that one solution is $x=r$, we can substitute $x$ with $r$ in the left side to verify that it satisfies the equation:

$(r-p)(r-q) = r^2 - (p+q)r + pq$

Now, we can see that the equation is quadratic in $x$, and we have one solution $x=r$. The quadratic equation will have two solutions, and the other solution can be found using the quadratic formula or by recognizing that the sum of the roots of a quadratic equation $ax^2 + bx + c = 0$ is $-b/a$. In our case, the sum of the roots is $(p+q)/1 = p+q$.

Since we already have one root $x=r$, the other root $x'$ must satisfy:
$x' + r = p + q$

Solving for $x'$ gives us:
$x' = p + q - r$

Therefore, the other solution in terms of $p$, $q$, and $r$ is $x = p + q - r$.

The correct answer is:
D. p+q-r
D
kimi To solve this problem, let's first expand the given equation:

\[
(x-p)(x-q) = (r-p)(r-q)
\]

Expanding both sides, we get:

\[
x^2 - (p+q)x + pq = r^2 - (p+q)r + pq
\]

Now, since we know one solution is \( x = r \), we can substitute \( x = r \) into the equation to verify:

\[
r^2 - (p+q)r + pq = r^2 - (p+q)r + pq
\]

This is true, so \( x = r \) is indeed a solution.

Now, we want to find the other solution. Let's rearrange the equation to isolate the terms involving \( x \):

\[
x^2 - (p+q)x + pq - r^2 + (p+q)r - pq = 0
\]

Simplifying, we get:

\[
x^2 - (p+q)x + (p+q)r - r^2 = 0
\]

This is a quadratic equation in the form \( ax^2 + bx + c = 0 \). We can use the quadratic formula to solve for \( x \), but since we already know one solution is \( x = r \), we can use the fact that the sum of the roots of a quadratic equation \( ax^2 + bx + c = 0 \) is \( -b/a \).

In our case, \( a = 1 \) and \( b = -(p+q) \), so the sum of the roots is:

\[
x_1 + x_2 = p + q
\]

Since \( x_1 = r \), the other root \( x_2 \) can be found by:

\[
r + x_2 = p + q
\]

Solving for \( x_2 \), we get:

\[
x_2 = p + q - r
\]

So the other solution is \( p + q - r \), which corresponds to:

\[
\boxed{D}
\]
D
wenxinyiyan D. p+q-r.

Explanation:
Given the equation $(x-p)(x-q) = (r-p)(r-q)$, we can expand both sides to get:
$x^2 - px - qx + pq = r^2 - pr - qr + pq$.
Simplifying, we have:
$x^2 - (p+q)x = r^2 - (p+q)r$.
Now, we can factor the left and right sides to get:
$(x-r)(x+r-p-q) = 0$.
From this, we see that one solution is $x = r$, as given in the problem. The other solution is $x = p+q-r$.
D
zhipu To solve the given equation \((x-p)(x-q) = (r-p)(r-q)\) and find the other solution in terms of \(p\), \(q\), and \(r\), we start by noting that \(x = r\) is one solution.

First, substitute \(x = r\) into the equation:
\[
(r-p)(r-q) = (r-p)(r-q)
\]
This is true, confirming that \(x = r\) is indeed a solution.

To find the other solution, let's expand both sides of the equation:
\[
(x-p)(x-q) = x^2 - (p+q)x + pq
\]
\[
(r-p)(r-q) = r^2 - (p+q)r + pq
\]

Since the equation is given as:
\[
x^2 - (p+q)x + pq = r^2 - (p+q)r + pq
\]

We can subtract \(pq\) from both sides:
\[
x^2 - (p+q)x = r^2 - (p+q)r
\]

Rearrange the equation:
\[
x^2 - (p+q)x - (r^2 - (p+q)r) = 0
\]

This is a quadratic equation in the form \(ax^2 + bx + c = 0\), where:
\[
a = 1, \quad b = -(p+q), \quad c = -(r^2 - (p+q)r)
\]

We know one solution is \(x = r\). Let the other solution be \(x = s\). By Vieta's formulas for a quadratic equation \(ax^2 + bx + c = 0\), the sum of the roots is given by:
\[
r + s = -\frac{b}{a} = p + q
\]

So, solving for \(s\):
\[
s = p + q - r
\]

Thus, the other solution in terms of \(p\), \(q\), and \(r\) is:
\[
\boxed{p + q - r}
\]

Therefore, the correct answer is:
D. \(p + q - r\)
D
gpto1 D D
deepseekv3 To solve the equation \((x-p)(x-q) = (r-p)(r-q)\) and find the other solution besides \(x = r\), follow these steps:

1. **Expand both sides:**
\[
(x - p)(x - q) = x^2 - (p + q)x + pq
\]
\[
(r - p)(r - q) = r^2 - (p + q)r + pq
\]

2. **Set the expanded forms equal:**
\[
x^2 - (p + q)x + pq = r^2 - (p + q)r + pq
\]

3. **Simplify the equation:**
\[
x^2 - (p + q)x = r^2 - (p + q)r
\]
\[
x^2 - (p + q)x - r^2 + (p + q)r = 0
\]
\[
x^2 - (p + q)x + (p + q)r - r^2 = 0
\]

4. **Factor the quadratic equation:**
Notice that \(x = r\) is a solution, so \((x - r)\) is a factor. Use polynomial division or synthetic division to factor the quadratic:
\[
(x - r)(x - (p + q - r)) = 0
\]

5. **Find the other solution:**
The solutions are \(x = r\) and \(x = p + q - r\).

Thus, the other solution is \(x = p + q - r\).

**Answer:** \(\boxed{D}\)
D