Jawabanmu

2014-06-01T14:31:15+07:00
L persegi panjang = p . l
120 = (3x-3)8
120 = (8 . 3x) - (8.3)
120 = 24x - 24
120 +24 =24x
144 = 24x
x = 144 : 24 = 6
panjang = 3x-3
panjang = 3(6)-3
panjang = 18 - 3 = 15 cm