assalamualaikum. tolong yang bisa bantu jawab...

f(x) = 3x-5
g(x) = 2x²+1
(f•g)(x) = 3(2x²+1)-5 = 6x²-2

(f•g)(x) = 4
6x²-2 = 4
6x² - 6 = 0 (÷6)
x² - 1 = 0
(x+1)(x-1) = 0
x = -1 atau x = 1


jawaban : B

jawab

fog(x) =4
f (g(x)) = 4
f(2x^2 +1) = 4
3(2x^2 +1) - 5 = 4
3(2x^2 +1) =4 +5 = 9
2x^2 +1 = 9/3 = 3
2x^2 = 3 -1 =2
x^2  = 1
x = 1 atau x = -1