S/D
X/4 - 3 = 25
X =7
5x - 5 = 30
X=7
5x + 3 = 28
C = 5
X/7 + 6 = 55
X = 7
X + 12 = 135
X = 123
X/5 - 5 = 20
X=5
6x - 7 = 35
X = 7
9x + 9 = 99
X = 10
X/6 + 2 =38
X = 6
X + 18 = 127
X = 109
X/7 - 3 = 18
X = 3
3x - 6 = 30
X = 12
3x + 12 = 45
X = 11
X/5 + 12 = 37
X = 5
X + 13 = 201
X = 188
X/8 - 5 = 35
X = 5
5x - 10 = 30
X = 8
7x + 13 = 76
X = 9
X/4 + 13 = 37
X = 6
X + 19 = 325
X = 306
X/10 - 10 = 90
X = 10
4x - 6 = 30
X = 9
8x + 16 = 104
X = 11
X/6 + 12 = 78
X = 11
X + 18 = 475
X = 457