1、(4/5+5/4)×4+13/10=(16+25)/20×4+13/10=62/10+13/10=75/10=7.5 2、72+72×5/9=72×(1+5/9)=72×14/9=8×14=112 3、8x-3/4=45/4 32x-3=45 32x=42 x=21/16 4、(x-6)×5/6=25 x-6=25×6/5 x-6=30 x=36 5、x:7/10=5/28 x×10/7=5/28 x=5/28×7/10 x=1/8