Tentukan nilai x, y dan z

X + y + z = 45
x + (x + 4) + z = 45
2x + z + 4 = 45
2x + z = 41
2(z – 17) + z = 41
2z – 34 + z = 41
3z = 75
z = 25

sub nilai z = 25 ke pers z – 17 = x
25 – 17 = x
8 = x

sub nilai x = 8 ke pers x + 4 = y
8 + 4 = y
12 = y

jadi nilai x = 8, y = 12, z = 25