Jawabanmu

2014-05-23T20:20:04+07:00
3x  = x + 21
 2        3
9x = 2x + 42
9x - 2x = 42
7x = 42
x = 42/7 = 6
2014-05-24T03:57:48+07:00
 \frac{3}{2}x =  \frac{x}{3}  + 7
3(3x) = 2 (x+7)
9x = 2x +14
7x = 14
x =  \frac{14}{7}
x=2