## Geometry: Common Core (15th Edition)

The solution is $(5, 2)$.
Let's solve one of the equations for one of the variables, and then use that equation to substitute into the other equation. Let's solve the second equation for $x$: $x + 2y = 9$ Subtract $2y$ from each side of the equation to solve for $x$: $x = -2y + 9$ We can use this equation to substitute for $x$ in the first equation. Then we can solve for $y$ first: $2(-2y + 9) - y = 8$ Use distribution to get rid of the parentheses: $-4y + 18 - y = 8$ Combine the $y$ terms: $-5y + 18 = 8$ Move constants to the right side of the equation by subtracting $18$ from each side of the equation: $-5y = -10$ Divide each side of the equation by $-5$ to solve for $y$: $y = 2$ Now that we have the value for $y$, let's plug this value for $y$ into the first equation: $2x - 2 = 8$ Add $2$ to each side of the equation to move constants to the right side of the equation: $2x = 10$ Divide each side by $2$ to solve for $x$: $x = 5$ The solution is $(5, 2)$.