Jawabanmu

2014-04-20T21:22:52+07:00
180 = 3x -9 +2x + 4 
180= 5x-5
185=5x
37=x

M= 3x-9
    =(3x37)-9
    =111-9
    =102
1 4 1
2014-04-20T21:42:32+07:00
⇒M + N = 180
 3x - 9 + 2x + 4 = 180
 5x - 5 = 180
 5x = 180 + 5
 x = 185 : 5 = 37
⇒M = 3x - 9
       =3 . 37 - 9 = 111 - 9 = 102