问题


There is a single choice question about high school mathematics. Answer the question by replying A, B, C or D.
Question: Find $b$ if $\log_{b}343=-\frac{3}{2}$.
A. 3
B. \frac{1}{49}
C. \frac{1}{7}
D. 7
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0 B. \frac{1}{49} B
deepseekr1

To solve for \( b \) in the equation \( \log_{b}343 = -\frac{3}{2} \), we first convert the logarithmic form to its exponential equivalent:
\[
b^{-\frac{3}{2}} = 343.
\]
Next, express \( 343 \) as \( 7^3 \):
\[
b^{-\frac{3}{2}} = 7^3.
\]
Raise both sides to the power of \(-\frac{2}{3}\) to isolate \( b \):
\[
\left(b^{-\frac{3}{2}}\right)^{-\frac{2}{3}} = \left(7^3\right)^{-\frac{2}{3}}.
\]
Simplifying the exponents on both sides:
\[
b^{\left(-\frac{3}{2} \times -\frac{2}{3}\right)} = 7^{3 \times -\frac{2}{3}},
\]
\[
b^1 = 7^{-2}.
\]
This simplifies to:
\[
b = \frac{1}{7^2} = \frac{1}{49}.
\]
Verification confirms that \( \log_{\frac{1}{49}}343 = -\frac{3}{2} \) holds true. Thus, the correct answer is **B**.

**Answer: B**
B
gpto1 B B
GPT-4o To solve for \( b \) if \( \log_{b}343=-\frac{3}{2} \), we can rewrite the logarithmic equation in its exponential form. The equation \( \log_{b}343 = -\frac{3}{2} \) translates to:

\[ b^{-\frac{3}{2}} = 343 \]

Next, to isolate \( b \), we can rewrite the equation:

\[ b^{-\frac{3}{2}} = 343 \]

Taking the reciprocal of both sides to get rid of the negative exponent:

\[ b^{\frac{3}{2}} = \frac{1}{343} \]

Now, express \( 343 \) as a power of 7:

\[ 343 = 7^3 \]

Thus,

\[ b^{\frac{3}{2}} = \frac{1}{7^3} = 7^{-3} \]

Equating the exponents, we get:

\[ b^{\frac{3}{2}} = 7^{-3} \]

Therefore, taking the reciprocal of both sides again to find \( b \):

\[ b = 7^{-2} \]

Simplifying:

\[ b = \frac{1}{7^2} = \frac{1}{49} \]

Thus, the correct answer is:

B. \(\frac{1}{49}\)
B
llama3.1-70B-Instruct

B
B
llama3.1-405B-Instruct

C
B
DeepSeek-Coder-V2 C B
Qwen2-72B-Instruct B. \frac{1}{49} B
baichuan4 D B
doubao We can rewrite 343 as 7^3. So the equation becomes $\log_{b}7^3=-\frac{3}{2}$. Then $3\log_{b}7=-\frac{3}{2}$. $\log_{b}7=-\frac{1}{2}$. Rewrite it in exponential form: $b^{-\frac{1}{2}}=7$. So $\frac{1}{\sqrt{b}}=7$, $b=\frac{1}{49}$.

So the answer is B.
B
minimax To find $b$ given that $\log_{b}343=-\frac{3}{2}$, we can rewrite the logarithmic equation in exponential form. The equation $\log_{b}343=-\frac{3}{2}$ means that $b$ raised to the power of $-\frac{3}{2}$ equals 343.

So, we have:

$$ b^{-\frac{3}{2}} = 343 $$

To solve for $b$, we can take the reciprocal of both sides and then raise both sides to the power of $-\frac{2}{3}$:

$$ b^{\frac{3}{2}} = \frac{1}{343} $$

$$ (b^{\frac{3}{2}})^{\frac{2}{3}} = \left(\frac{1}{343}\right)^{\frac{2}{3}} $$

$$ b = \left(\frac{1}{343}\right)^{\frac{2}{3}} $$

Since $343 = 7^3$, we can rewrite the equation as:

$$ b = \left(\frac{1}{7^3}\right)^{\frac{2}{3}} $$

$$ b = \frac{1}{(7^3)^{\frac{2}{3}}} $$

$$ b = \frac{1}{7^{3 \cdot \frac{2}{3}}} $$

$$ b = \frac{1}{7^2} $$

$$ b = \frac{1}{49} $$

Therefore, the correct answer is:

B. $\frac{1}{49}$
B
kimi To solve the equation $\log_{b}343=-\frac{3}{2}$, we can convert the logarithmic equation to its exponential form:

$b^{-\frac{3}{2}} = 343$

Since $343 = 7^3$, we can rewrite the equation as:

$b^{-\frac{3}{2}} = 7^3$

Now, we want to find the value of $b$ that satisfies this equation. We can rewrite the exponent on the left side to have a positive exponent by taking the reciprocal of both sides:

$b^{\frac{3}{2}} = \frac{1}{7^3}$

$b^{\frac{3}{2}} = \frac{1}{343}$

Now, we raise both sides to the power of $\frac{2}{3}$ to solve for $b$:

$b = \left(\frac{1}{343}\right)^{\frac{2}{3}}$

$b = \left(\frac{1}{7^3}\right)^{\frac{2}{3}}$

$b = \frac{1}{7^2}$

$b = \frac{1}{49}$

So the correct answer is:

B. $\frac{1}{49}$
B
wenxinyiyan B

### Explanation:

Given the equation $\log_{b}343 = -\frac{3}{2}$, we can convert it to exponential form as follows:

$b^{-\frac{3}{2}} = 343$

Since $343 = 7^3$, we can write:

$b^{-\frac{3}{2}} = 7^3$

Taking the reciprocal and square root on both sides, we get:

$b^{\frac{3}{2}} = \frac{1}{7^3}$

$b^{\frac{3}{2}} = \left(\frac{1}{7}\right)^3$

$b^{\frac{3}{2}} = \left(\frac{1}{7}\right)^{2 \times \frac{3}{2}}$

$b = \left(\left(\frac{1}{7}\right)^2\right)^{\frac{3}{2} \times \frac{2}{3}}$

$b = \left(\frac{1}{49}\right)^1$

$b = \frac{1}{49}$
B
zhipu To solve the equation \(\log_{b}343 = -\frac{3}{2}\), we need to rewrite it in exponential form. The logarithmic equation \(\log_{b}343 = -\frac{3}{2}\) is equivalent to:

\[ b^{-\frac{3}{2}} = 343 \]

We know that \(343\) can be expressed as \(7^3\), so we substitute this into the equation:

\[ b^{-\frac{3}{2}} = 7^3 \]

Next, we simplify the equation by taking the cube root of both sides to eliminate the exponent \(-\frac{3}{2}\):

\[ \left(b^{-\frac{3}{2}}\right)^{\frac{1}{3}} = \left(7^3\right)^{\frac{1}{3}} \]

This simplifies to:

\[ b^{-\frac{1}{2}} = 7 \]

To isolate \(b\), we square both sides of the equation:

\[ \left(b^{-\frac{1}{2}}\right)^2 = 7^2 \]

This gives us:

\[ b^{-1} = 49 \]

Finally, we take the reciprocal of both sides to solve for \(b\):

\[ b = \frac{1}{49} \]

Thus, the correct answer is:

B. \(\frac{1}{49}\)
B
gpto1 B B
deepseekv3 To solve for \( b \) in the equation \(\log_{b}343 = -\frac{3}{2}\), follow these steps:

1. **Convert the logarithmic equation to its exponential form:**
\[
\log_{b}343 = -\frac{3}{2} \implies b^{-\frac{3}{2}} = 343
\]

2. **Express 343 as a power of 7:**
\[
343 = 7^3
\]

3. **Substitute back into the equation:**
\[
b^{-\frac{3}{2}} = 7^3
\]

4. **Take the reciprocal to eliminate the negative exponent:**
\[
b^{\frac{3}{2}} = 7^{-3}
\]

5. **Express both sides with the same exponent:**
\[
b^{\frac{3}{2}} = \left(7^{-2}\right)^{\frac{3}{2}}
\]

6. **Since the exponents are equal, set the bases equal:**
\[
b = 7^{-2} = \frac{1}{49}
\]

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