compositions algebra 2

Question

given f(x)=x^2+3. evaluate f(x+h)-f(x)

Answer 1

f(x) = x² + 3

f(x+h) = (x+h)² + 3 = x² + 2xh + h² + 3

Can you finish it?

f(x+h) - f(x) = _____?