Jika f(x)=2x+3 dan g(x)=9-x, nilai dr (fog) -¹(-9)=

f(x) = 2x + 3
g(x) = 9 - x

(fog)(x) = 2(9 - x) + 3 = 21 - 2x

(fog)^-1 (21 - 2x) = x
(fog)^-1 (-9) = x

21 - 2x = -9
2x = 21 + 9
x = 30/2
x = 15

(fog)^-1 (-9) = x = 15

2x+x=3x
3-9=-6
-6+9=3
3x+3=0
X+1==0