(720+е) * 501 = 365730

720 + е = 365730 / 501

720 + е = 730

е = 730 - 720

е = 10

5t + 30 - 12t = 42

5t - 12t = 42 - 30

-7t  = 12

t = - 12 / 7

t = - 1 5/7

36 *(x-3) = 10 - 2(x+2)

36x - 108 = 10 - 2x - 4

36x + 2x = 108 + 10 - 4

38x = 114

x = 114/38

x = 3