Answer:
[tex]\large\boxed{x=\dfrac{83}{13}\ and\ y=\dfrac{22}{13}}[/tex]
Step-by-step explanation:
[tex]\left\{\begin{array}{ccc}5x=15+10y&\text{divide both sides by 5}\\3x+7y=31\end{array}\right\\\left\{\begin{array}{ccc}x=3+2y&(1)\\3x+7y=31&(2)\end{array}\right\\\\\text{substitute (1) to (2):}\\\\3(3+2y)+7y=31\qquad\text{use distributive property}\\(3)(3)+(3)(2y)+7y=31\\9+6y+7y=31\qquad\text{subtract 9 from both sides}\\13y=22\qquad\text{divide both sides by 13}\\\boxed{y=\dfrac{22}{13}}[/tex]
[tex]\text{Put the value of y to (1):}\\\\x=3+2\left(\dfrac{22}{13}\right)\\\\x=\dfrac{39}{13}+\dfrac{44}{13}\\\\\boxed{x=\dfrac{83}{13}}[/tex]
