5(x-2)+3x=118

раскроем скобки

5x-10+3x = 118

8x-128 = 0

8x = 128

x = 16

31x-2(-315-14)=134

раскроем скобки

31x+630+28 = 134

31x+524 = 0

31x = -524

x = -524/31

х=-16,9032258065