a) \(175-\left(42:x+95\right)=3\)
\(\Rightarrow42:x+95=172\)
\(\Rightarrow42:x=77\)
\(\Rightarrow x=42:77\)
\(\Rightarrow x=\dfrac{6}{11}\)
b) \(450:\left(75-13\cdot x\right)=10\)
\(\Rightarrow75-13\cdot x=450:10\)
\(\Rightarrow75-13\cdot x=45\)
\(\Rightarrow13\cdot x=75-45\)
\(\Rightarrow13\cdot x=30\)
\(\Rightarrow x=\dfrac{30}{13}\)