5/7*5.5+550%*2/7+11除以2
=5/7*5.5+5.5*2/7+5.5
=（5/7+2/7+1）*5.5
=2*5.5
=11
（6-1/8*32）除以3/4
=(6-1/4)*4/3
=6*4/3-1/4*4/3
=8-1/3
=7又2/3
解方程
60%x+25=40
移项
0.6x=40-25
0.6x=15
x=15÷0.6
x=25
x-20%x=2
(1-20%)x=2
0.8x=2
x=2÷0.8
x=2.5