Question

5(x – 2) = 100 b) –3(y – 4) = 90 c) 2(3x + 3) = 66 d) –9(x – 10) = 360

Answer 1

a) 5x - 10 = 100
    5x = 110
     x = 110/5
       x = 22
b) - 3y + 12 = 90
     - 3y = 78 (-1)
        y = -78 /3
          y = - 26
c) 6x + 6 = 66
    6x = 60
      x = 60/6
        x = 10
d) - 9x + 90 = 360 
     - 9 x = 270 (-1)
          x = -270/9
           x = - 30               ok

Answer 2

5(x – 2) = 100
5x - 10 = 100
5x = 100+10
5х = 110
x = 110 : 5
x = 22
___________________-
–3(y – 4) = 90
- 3y + 12 = 90
- 3y  = 90 - 12
- 3y = 78 
 3y = -78
у = (-78) : 3
y = - 26
_____________________-
6x + 6 = 66
6x = 66 - 6
6x = 60
x = 60 : 6
x = 10
----------------------------------------
- 9x + 90 = 360
- 9x = 360 - 90
- 9x = 270 
9x = - 270 
 x = (- 270) : 9
 x = - 30