Question

Maaf.. yang bisa tolong bantu ya...

jika di ketahui f(x) = 1 - 3x dan g(x)= x - 2 f(x) maka harga f(g(1)) adalah...

Answer 1

G(x) = x-2
g(1) = 1 -2 = -1

f(x) = 1-3x
f(g(1)) = 1-3(-1) = 1+3 = 4

Answer 2

g(x) = x - 2f(x)
g(x) = x - 2(f(x)
g(x) = x - 2(1 - 3x)
g(x) = x - 2 + 6x
g(x) = 7x - 2
g(1) = 7(1) - 2
g(1) = 7 - 2
g(1) = 5

f(g(1)) = ....?
f(g(1)) = f(5)
f(g(1)) = 1 - 3(5)
f(g(1)) = 1 - 15
f(g(1)) = -14

cara lain

g(x) = x - 2f(x)
g(x) = x - 2(f(x)
g(x) = x - 2(1 - 3x)
g(x) = x - 2 + 6x
g(x) = 7x - 2

f(g(x)) = (f o g)(x)
f(g(x)) = 1 - 3(7x - 2)
f(g(x)) = 1 - 21x + 6
f(g(x)) = 7 - 21x
f(g(1)) = 7 - 21(1)
f(g(1)) = 7 - 21
f(g(1)) = -14