Question

What is f(3) if f(x) =2x+6

Answer 1

F(3) = 2(3)+6
f(3)= 6+6
f(3)=12

Hope this helps!

Answer 2

Replace f(x) with y
Y=2x-6

Interchange the variables
X=2y-6

Solve for y
Y=3+x/2

F to the negative 1st power (x)=3+x/2