a) 10+2x=45:43
10+2x=42
10+2x=16
2x=16-10
2x=6
x=6:2
x=3
vậy x=3
b)130-(100+x)=25
100+x=130-25
100+x=105
x=105-100
x=5
vậy x=5
c)22.(x+32)-5=55
4.(x+9)=55+5
x+9=60:4
x+9=15
x=15-9
x=6
vậy x=9
d)72-7(13-x)=14
49-7(13-x)=14
7(13-x)=49-14
13-x=35:7
13-x=5
x=13-5
x=8
vậy x=8