If f(X)=x^2-5, evaluate (f(x+h)-f(x))/h

Question

F(x)=x²-5, evaluate f(x+h)-f(x)

h

Answer 1

f(x) = x² - 5

[f(x+h - f(x)] / h = [(x+h)² - 5 - (x² - 5)] / h

= [x² + 2xh + h² - 5 - x² + 5] / h

= (2xh + h²) / h = h(2x + h) / h = 2x + h