## Algebra 1: Common Core (15th Edition)

$x = 15$ $y = -0.5$
$3x + 6y = 42$ $-7x + 8y = -109$ To use elimination, we need to make one of the variables the same in each equation: $21x + 42y = 294$ $-21x + 24y = -327$ Add the two equations together: $66y = -33$ Divide each side by $66$ to solve for $y$: $y = -0.5$ Now that we have the value for $y$, we can plug it into one of the equations to solve for $x$: $3x + 6(-0.5) = 42$ Multiply first: $3x - 3 = 42$ Add $3$ to each side of the equation: $3x = 45$ Divide each side of the equation by $3$: $x = 15$