f(2x + 4) = 4x + 2 f(5) = ? Tolong dibantu yaa, pakai cara juga plixzz

misal :
2x+4 = y
2x = y - 4
x = y-4 /2

f(y) = 4(y-4/2) +2
f(y) = 2y -8 + 2
f(y) = 2y -6

f(x) = 2x - 6

f(5) = 2(5) - 6
f(5) = 10 -6
f(5) = 4