-4/15 x+12=4/45 x
解:
两边同乘以45得:
-12x+12*45=4x
16x=12*45
x=12*45/16
x=135/4
-4/15 x+12=4/45 x
4/45 x+4/15 x=12
4/45 x+12/45 x=12
16/45 x=12
x=135/4
-4/15x-45/4x+12=0
-16/60x-675/60x+12=0
-691/60x+12=0
x=720/691