X-25%X=30
X-0.25X=30
0.75X=30
X=30÷0.75
X=40
2X+30%X=9.2
2.3X=9.2
X=9.2÷2.3
X=4
75%X-45%X=12
0.3X=12
X=12÷0.3
X=40
X+120%X=33
2.2X=33
X=33÷2.2
X=15
x=44
X-25%X=30
0.75X=30
X=30/0.75
X=40
2X+30%X=9.2
2.3X=9.2
X=9.2/2.3
X=4
75%X-45%X=12
0.3X=12
X=12/0.3
X=40
X+120%X=33
2.2X=33
X=33/2.2
X=15
1、40 2、4 3、15