Explanation:
-15
Firstly, write \(\frac{-3}{7}\) as a rational number with denominator 35.
Multiplying the numerator and denominator of \(\frac{-3}{7}\) by 5,
We have:
\(\frac{-3}{7}=\frac{-3\times5}{7\times5}=\frac{-15}{35}\)
\(\therefore\frac{-3}{7}=\frac{\text{x}}{35}\)
\(\Rightarrow\frac{-15}{35}=\frac{\text{x}}{35}\)
\(\Rightarrow\text{x}=-15\)
Hence, the correct answer is option (c).