f(x) = x? & g(x) = 2x + 1
(f+g)(x) = f(x) + g(x)
= (x2) + (2x + 1)
= x2 + 2x + 1,
(f + g) (x) = x2 + 2x + 1
(f-g)(x) = f(x) - g(x)
= (x2) - (2x + 1)
