Jawabanmu

2014-05-29T18:44:27+07:00
81 = 18 x 2x+3 : 2
81 = 9 x2x+3
9 = 2x+ 3
6 = 2x
x = 3
2014-05-29T18:57:20+07:00
81 = d1 x d2 / 2
81 = 18 x (2x+3) / 2
81.2 = 18 x (2x + 3)
162 = 18 x (2x + 3)
162 = 54 x  36x
162 : 54 = 36x
3 = 36x
x = 36/3
x = 12