0.12x-3/5x=0.72x
0.12X+3/5X=0.72X
0.12 X+3/5 X=多少?0.12 X+3/5 X=12/100x+3/5x=(12/100+60/100)x=72/100x=0.72x
∴12/100X十3/5x3/25x十18/25x二21/25x