Question

Given
`f(x)=9x^2+7x` and
`g(x)=2-x`, determine
`5g(x)-f(x)`

A.
`45^2+36x-2`
B.
`45x^2+6x-5`
C.
`9x+6x+2`
D.
`-9x-12x+10`

Answer 1

f(x) = 9x² + 7x

g(x) = 2 - x

= 5g(x) - f(x)

= 5(2-x) - (9x² + 7x)

= 10 - 5x - 9x² - 7x

= 10 - 12x - 9x²

= 10 - 12x - 9x²= 9x² - 12x + 10.

D is the correct option.