Answer :
All you do here is plug in 4 for the x values.
So F(4)=4^2-1 which is F(4)=16-1 so F(4)= 15
So G(4)= 3(4)+1 which is G(4)=12+1 so G(4)=13
So F(4)=4^2-1 which is F(4)=16-1 so F(4)= 15
So G(4)= 3(4)+1 which is G(4)=12+1 so G(4)=13