dik (x)=3x-6 dan g(x)=2x+a. bila f0g(x)=g0f(x) maka nilai a adalah

fog = 3 (2x + a) - 6
gof = 2 (3x - 6) + a

fog = gof
3 (2x + a) - 6 = 2 (3x - 6) + a
6x + 3a - 6 = 6x - 12 + a
3a - a = 6x - 6x - 12 + 6
2a = -6
a = -3
#semogabermanfaat

Bab Fungsi Komposisi
Matematika SMA Kelas X

(fog) (x) = (gof) (x)
f(2x + a) = g(3x - 6)
3 (2x + a) - 6 = 2(3x - 6) + a 
6x + 3a - 6 = 6x - 12 + a
** coret 6x **

3a - 6 = - 12 + a
3a - a = - 12 + 6
2a = - 6
a = -6 : 2
a = -3