Question

What is x ?
x + 5 + 2x = x + 15

Answer 1

x = 5

Explanation:

`x+5+2x=x+15\qquad\text{combine like terms}\\\\(x+2x)+5=x+15\\\\3x+5=x+15\qquad\text{subtract 5 from both sides}\\\\3x+5-5=x+15-5\\\\3x=x+10\qquad\text{subtract}\ x\ \text{from both sides}\\\\3x-x=x-x+10\\\\2x=10\qquad\text{divide both sides by 2}\\\\(2x)/(2)=(10)/(2)\\\\x=5`

Answer 2

x + 5 + 2x = x + 15 = 3x + 5
5 + 2x = 15 = 2x + 5
2x = 10 = 2x
x = 5