1.
20/(1/3-2/3*1/4)=120
2倍
2.
20/(1-1/3-1/4(2/3x-20)-3/8)=x
x=180
180*3/8=75
3.(52+28)/(3/4+2/3-1)=16*12=192
4.(200-56)/(25%+1/5)*1/5=64
5.25%:1/5=5:4
54/(5+4)*5=30
54-30=24
6.x+y=2500
2/3x+3/4y=1750
x=1500
y=1000
7.2/5x+1/4y=708
x+y=2268
x=940
y=1328
8.1/4:20%=5:4
60*5=300
540-300=240
9.1/4x+1/5y=50
x+y=220
x=120
y=100
10.
24y+30x=900
32y+30(y-x)=1250
y=2150/86=25
x=10