$ 5x+\frac{1}{2}=40 \Rightarrow 5x=40\frac{1}{2} \Rightarrow 5x= \frac{79}{2} \Rightarrow x =\frac{79}{10} \\ 2x+\frac{1}{5}= 2\times \frac{79}{10}+\frac{1}{5} = \frac{80}{5}=16 $