jika f(x) = 2x-1 dan (f o g)(x) = -14x + 21, nilai dari g(-3) = ....

jawab

f(x) = 2x - 2
fog(x) = - 14x + 21
f{(g(x)} = -14x  + 21

2 g(x) - 2 = -14x + 21
2 g(x)= -14x + 23
g(x)= 1/2 (-14x + 23)
g(-3) = 1/2 ( -14(-3) + 23)
= 1/2 (42+ 23)
= 1/2 (65)
= 65/2