Answer :
(10,40)
Explanation
Step 1
[tex]\begin{gathered} y=f(x) \\ (10,20)\rightarrow y=f(x)\rightarrow20=f(10) \\ 20=f(10) \end{gathered}[/tex]Step 2
now
[tex]\begin{gathered} y^{\prime}=2\cdot f(x) \\ y^{\prime}=2\cdot f(10) \\ y^{\prime}=2\cdot20 \\ y^{\prime}=40 \\ \text{then} \\ (10,40) \end{gathered}[/tex]