jika f(x)=x-8, g(x)=2x2+3 dan f o g(x)=25 maka x?

f(x) = x -8 dan g(x) = 2x^2 +3
fog(x) = 25
f { g(x) } = 25
f (2x^2 +3) = 25
2x^2 + 3 -8 =25
2x^2 - 5 -25 =0
2x^2-- 30 = 0
x^2- 15 =0
x^2 = 15
x = +/- akar 15