问题


There is a single choice question about high school mathematics. Answer the question by replying A, B, C or D.
Question: Factor $36-9x^2$.
A. (6-3x)(6+3x)
B. (-3x+6)(3x+6)
C. 9(2-x)(2+x)
D. 3(2+x)^2
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0 C. 9(2-x)(2+x) C
deepseekr1

The expression \(36 - 9x^2\) can be factored using the difference of squares formula \(a^2 - b^2 = (a - b)(a + b)\). First, rewrite the expression as \(6^2 - (3x)^2\), which factors into \((6 - 3x)(6 + 3x)\) (Option A). However, factoring out the greatest common factor (GCF) first simplifies the process further. The GCF of 36 and \(9x^2\) is 9, so:

\[
36 - 9x^2 = 9(4 - x^2).
\]

Next, \(4 - x^2\) is another difference of squares (\(2^2 - x^2\)), leading to:

\[
9(4 - x^2) = 9(2 - x)(2 + x),
\]

which matches **Option C**. While Options A and B are algebraically equivalent to each other and correct, they do not factor out the GCF. Option C provides the most complete factorization by including the GCF. Thus, the best answer is:

**C. 9(2-x)(2+x)**.

**Answer: C**
C
gpto1 C C
GPT-4o A. (6-3x)(6+3x) C
llama3.1-70B-Instruct

A
C
llama3.1-405B-Instruct

A. (6-3x)(6+3x)
C
DeepSeek-Coder-V2 C. 9(2-x)(2+x) C
Qwen2-72B-Instruct C. 9(2-x)(2+x) C
baichuan4 C C
doubao C. 9(2-x)(2+x)

$36-9x^2=9(4-x^2)=9(2-x)(2+x)$.
C
minimax The expression $36-9x^2$ is a difference of squares, which can be factored as $a^2 - b^2 = (a - b)(a + b)$.

Here, $a^2 = 36$ and $b^2 = 9x^2$, so $a = 6$ and $b = 3x$.

Applying the difference of squares formula, we get:

$36 - 9x^2 = (6)^2 - (3x)^2 = (6 - 3x)(6 + 3x)$.

Therefore, the correct answer is:

A. $(6-3x)(6+3x)$
C
kimi To factor the expression \(36 - 9x^2\), we can first recognize it as a difference of squares. The difference of squares formula is \(a^2 - b^2 = (a - b)(a + b)\). Here, \(a^2\) is \(36\) and \(b^2\) is \(9x^2\), which means \(a = 6\) and \(b = 3x\).

So, we can rewrite the expression as:
\[36 - 9x^2 = 6^2 - (3x)^2\]

Applying the difference of squares formula:
\[6^2 - (3x)^2 = (6 - 3x)(6 + 3x)\]

Therefore, the correct answer is:
A. \((6-3x)(6+3x)\)
C
wenxinyiyan C C
zhipu To factor \(36 - 9x^2\), we can recognize that it is a difference of squares. The general form for a difference of squares is \(a^2 - b^2 = (a - b)(a + b)\).

Here, \(36\) is \(6^2\) and \(9x^2\) is \((3x)^2\). So, we can rewrite the expression as:
\[ 36 - 9x^2 = 6^2 - (3x)^2 \]

Applying the difference of squares formula:
\[ 6^2 - (3x)^2 = (6 - 3x)(6 + 3x) \]

This matches option A:
\[ (6 - 3x)(6 + 3x) \]

So, the correct answer is:
A. (6-3x)(6+3x)
C
gpto1 C C
deepseekv3 To factor the expression \( 36 - 9x^2 \), follow these steps:

1. **Factor out the Greatest Common Factor (GCF):**
The GCF of \( 36 \) and \( 9x^2 \) is \( 9 \). So, we factor out \( 9 \):
\[
36 - 9x^2 = 9(4 - x^2)
\]

2. **Factor the Remaining Expression:**
The expression \( 4 - x^2 \) is a difference of squares, which can be factored as:
\[
4 - x^2 = (2 - x)(2 + x)
\]

3. **Combine the Factors:**
Putting it all together:
\[
36 - 9x^2 = 9(2 - x)(2 + x)
\]

Now, let's compare this with the given options:

A. \( (6 - 3x)(6 + 3x) \)
B. \( (-3x + 6)(3x + 6) \)
C. \( 9(2 - x)(2 + x) \)
D. \( 3(2 + x)^2 \)

The correct factorization is **C**.

\boxed{C}
C