1) 5*х+х-3*х+12=33-18 2) 9*х-2*х-5*х=64-6*7 3) 7*х-5*х+4*х-38=15*2+4

1) 5*x+x-3*x+12 = 33-18

12 + 3*x = 33-18

12 + 3*x = 15

x = 3 / (3)

x = 1

2) 9*x-2*x-5*x = 64-6*7

2*x = 64-6*7

2*x = 22

x = 22 / (2)

x = 11

3) 7*x-5*x+4*x-38 = 15*2+4

-38 + 6*x = 15*2+4

-38 + 6*x = 34

x = 72 / (6)

x = 12