Can someone me with this? having a hard time..as usual

Which of the following tables represents exponential functions?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

Which equation represents the model shown? a)1/3 divide 1/6 = 2 b)2/3 divide 1/6 = 2/18 c)1/3 divide 1/6 = 1/18 d)2/3 divide 1/6 =4