Question

F f(x) = 4 – x2 and g(x) = 6x, which expression is equivalent to (g – f)(3)?

Answer 1

f(x) = -x2 (squared)
g(x) = 6x


(g - f)(3) = 6(3) - (-(3)2 + 4)
(g - f)(3) = 18 - (-9 + 4)
(g - f)(3) = 18 - (-5)
(g - f)(3) = 18 + 5
(g - f)(3) = 23

Note: All of the number 2 means squared

Answer 2

(g – f)(3) = 23.

Explanation:

Given : f(x) = 4 – x² and g(x) = 6x .

To find : which expression is equivalent to (g – f)(3).

Solution : We have given f(x) = 4 – x² and g(x) = 6x .

(g – f)(3) = g (3 ) - f(3) .

g(x) = 6x

Plug x = 3 .

g(3) = 6 *3 .

g(3) = 18.

For f(x) = 4 – x².

Plug x = 3

f( 3) = 4 – (3)².

f(3) = 4 – 9.

f(3) = –5.

Then , (g – f)(3) = g (3 ) - f(3) .

Plugging the values

(g – f)(3) = 18 - (-5) .

(g – f)(3) = 18 + 5.

(g – f)(3) = 23.

Therefore, (g – f)(3) = 23.