Suppose that the functions g and h are defined for all real numbers x as follows. g(x)=3x +5 h(x)=4x Write the expressions for (g·h)(x) and (g+h)(x) and evaluate (g-h)(3).

Question

Suppose that the functions g and h are defined for all real numbers x as follows. g(x)=3x +5 h(x)=4x Write the expressions for (g·h)(x) and (g+h)(x) and evaluate (g-h)(3).

Answer 1

g(x) = 3x +5

h(x) = 4x

(g-h)(x) = g(x) -h(x) = 3x+5 -4x = -x+5

(g+h)(x) = g(x) + h(x) = 3x+5 +4x = 7x +5

(g-h)(3) = -3+5 = 2