5 + x = 9 + 3x...................?

5 + x = 9 + 3x

Subtract x from both sides:
5 + x - x = 9 + 3x - x

5 = 9 + 2x

Subtract 9 from both sides:
5 - 9 = 9 - 9 + 2x

-4 = 2x

Divide by 2:
-4/2 = 2x/2

-2 = x

x = -2

5 + x = 9 + 3x
3x - x = 5 - 9
2x = - 4
x = - 4/2 or - 2

Answer: x = - 2

Proof:
5 + (- 2) = 9 + 3(- 2)
5 - 2 = 9 - 6
3 = 3

x= -2

5 + x = 9 + 3x
5 = 9 + 3x - x
5 = 9 + 2x
5 - 9 = 2x
-4 = 2x
-2 = x

5 + x = 9 + 3x
-3x + x = 9 - 5
-2x = 4
x = 4/(-2)
x = -2

5 - 9 = 3 x - x

- 4 = 2 x

x = - 2

Combine like-terms. That means get those that have x on them to one side, and those without a variable on the other side.


5 - 9 = 3x - x

-4 = 2x

-4/2 = x

-2 = x

5 + x = 9 + 3x
5 - 9 = 3x - x
-4 = 2x
2x = -4
x = -4/2 = -2

5 + x = 9 + 3x

Collect like terms

- 4 = 2x

x = - 2

5 + x = 9 + 3x
separate x from the other terms
x - 3x = 9 - 5
-2x = 4
x = -4/2
x = -2