I don't know what to do on these questions?

Question

1.Evaluate: (f(x+h) - f(x))/h and simplify if f(x)= x^2 + 2x

2. Eliminate the parameter and write a rectangular equation for:
x= t^2 +3
y= 2t

Answer 1

#1) {[(x+h)^2+2(x+h)]-(x^2+2x)}/h
[x^2+2xh+h^2+2x+2h-x^2-2x]/h FOIL and distribute in the numerator
(2xh+h^2+2h)/h combine like terms
2x+h+2 factor out and cancel an "h"

Answer 2

=((x+h)^2+2(x+h) -x^2-2x )/h= (x^2+2hx+h^2+2x+2h -x^2-2x)/h=
2x +2+h
x=t^2+3
y/2=t so x= (y/2)^2+3
x= y^2/4+3 ( parabola)

Answer 3

t=y/2

x=(y/2)^2+3=

y^2=4x-12