[tex]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}\\\\\dfrac{2x}{2}=\dfrac{10}{2}\\\\x=5[/tex]
