Question

If f(x) = 3x² + 2 and g(x)=x2-9, find (f- g)(x).

OA. 2x² - 7
OB. 2x² +11
OC. 4x²-7
OD. 4x² +11.

Answer 1

B. 2x² + 11

Explanation:

(f - g)(x) means:

f(x) - g(x)

We've been given what each of these is equal to, so substitute that in:

3x² + 2 - (x² - 9)

Simplify. Don't forget to distribute that minus in the middle to both terms in x² - 9

3x² + 2 - x² + 9

Next, combine like terms.

2x² + 11