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

Kekas 10 Matematika
Bab Fungsi Komposisi

(fog) (x) = 25
f(2x² + 3) = 25
2x² + 3 - 8 - 25 = 0
2x² - 30 = 0
x² - 15 = 0
(x + √15) (x - √15) = 0
x + √15 = 0
x = - √15

x - √15 = 0
x = √15