1、原式=65-（8*12.5%）*(5*3/5)
=65-1*3
=62
2、原式=（7/8-1/2)*8/9
=(7/8)*(8/9)-(1/2)*(8/9)
=7/9-4/9
=1/3
3、原式=（1/2-1/3*3/4)*4
=(1/2)*4-4*1/4
=2-1
=1