1 a 25 +X =40 X=15
b 18 +X=28 X=10
c 27+X=45 X=13
d 53+X=60 X=7
2a X+15=30 X=15
b X+30=100 X= 70
c X+44=86 X=42
d X+65=95 X=20
3a 30-X=12 X=18
b 25-X=18 X=13
c 55-x=22 X=11
d 100-X=32 X=68
4a X-18=22 X=2y6
b X-30=15 X=15
c X-55=45 X=10
d X-89=5 X=83
5a X+23=74 X=51
b X-34=74 X=108
c 91-X=52 X=29
d 105+X=130 X=25
6a X+23=65 X=42
b X-37=14 X=23
c 51-X=27 X=24
d 63-X=19 X=44
7a X+26=62 X=36
b X-18=45 X=63
c 60-X=23 X=37
d X-31=22 X=9
8a X-11=33 X=44
b 17+X=40 X=23
c X+29=37 X=8
d X-28=37 X=65