Answer:
(g o f)(- 4) = 570
Step-by-step explanation:
f(x)=4x+5
g(x)=4x² - 5x - 3
To find (g o f)(-4) we must first find
(g o f )(x)
To find (g of f)(x) substitute f(x) into g(x)
That's
(g o f)(x) = 4(4x + 5)² - 5(4x - 5) - 3
= 4( 16x² + 40x + 25) - 20x + 25 - 3
= 64x² + 160x + 100 - 20x + 22
(g o f)(x) = 64x² + 140x + 122
To find (g o f)(- 4) substitute the value of x that's - 4 into (g o f)(x)
Thats
(g o f)(- 4) = 64(-4)² + 140(-4) + 122
= 64(16) - 576 + 122
= 1024 - 454
We have the final answer as
(g o f)(- 4) = 570
Hope this helps you
