Question

If f : R → R is defined by f(x) = 10 x − 7, then write f⁻¹ (x).

Answer 1

$$\begin{gathered} \text{Let}{f}^{-1}\left(x\right)=y...\left(1\right) \\ \Rightarrow f\left(y\right)=x \\ \Rightarrow 10y-7=x \\ \Rightarrow 10y=x+7 \\ \Rightarrow y=\frac{x+7}{10} \\ \Rightarrow f^{-1}\left(x\right)=\frac{x+7}{10}\left(\text{From}\left(1\right)\right) \end{gathered}$$