f(x) 2x+5 (fog) (x) 13-2x tentukan a. g (x) b.(gof) (x)

jawab

fungsi
f(x) = 2x + 5
fog(x) = 13 - 2x
f{ g(x)} = 13 - 2x
2. g(x) + 5  = 13 - 2x
2. g(x) = 13 - 5 - 2x = 8 - 2x
g(x)= 4 - x

gof(x) = g { f(x)} = g (2x+ 5)
gof(x) = 4- (2x + 5) = 4 -2x - 5
gof(x) =  -2x - 1