jika f(x) = 3 - x dan g(x) = x² + 4x - 5 dan (g˚f) x = -9 nilai x...

f(x) = 3 - x
g(x) = x² + 4x - 5
(g○f)(x) = g/f(x)
-9 = (3-x)² + 4(3-x) - 5
-9 = 9 - 6x + x² + 12 - 4x- 5
-9 = 16 - 10x + x²
x² - 10x + 25 = 0
(x - 5)(x - 5)
x - 5 = 0
x = 5
Jadi nilai x = 5