Let f (x) = x²+3x-4 and g (x) = x+5 Find f (x) • g (x)

A) x³+3x²+16x-20

B) x³+5x²+14x-20

c) x³+8x²+11x-20

D) x³+9x²+19x-20

The correct option is C.

Step-by-step explanation:

Given:

f (x) = x²+3x-4 and g (x) = x+5

We have to find f (x) • g (x)

In this question simply multiply the functions:

(x²+3x-4) (x+5)

Multiply each element of 2nd bracket with the every element of first bracket.

= x (x²+3x-4) + 5 (x²+3x-4)

= x^3+3x^2-4x+5x^2+15x-20

Now solve the like terms:

= x^3+8x^2+11x-20

Thus the correct option is C ...

c) x^3 + 8x^2 + 11x - 20.

Step-by-step explanation:

f (x). g (x) = (x + 5) (x^2 + 3x - 4)

= x (x^2 + 3x - 4) + 5 (x^2 + 3x - 4)

= x^3 + 3x^2 - 4x + 5x^2 + 15x - 20 Simplifying like terms:

= x^3 + 8x^2 + 11x - 20.