Diketahui g(x)=3-2x dan (gof) (x) =x pangkat 2 -x+4 tentukan a. (fog) (x) b. (gof) (-5)

A.
(gof) (x)= x²-x+4
3-2(f(x))= x²-x+4
-2f(x) = x²-x+4-3
f(x) = x²-x+1 / -2
maka
(fog) (x) = (3-2x)²-(3-2x) +1 / -2
= 9-12x+4x²-3+2x+1 / -2
= 7+10x + 4x²
=-7/2 - 5x - 2x²

B.
f(-5)= (-5)²-(-5)+1 / -2
= 25+5+1 / -2
= 31/-2
g(31/-2)=3-2(31/-2)
=3+62
=65
jadi (gof))(-5)=65