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

$y=-x-4$ $4x-y=-1$ You can substitute $-x-4$ for y in the second equation so that $4x-(-x-4)=-1$. Then simplify $5x+4=-1$ and subtract 4 from both sides so that $5x=-5$. Lastly, divide by 5 on both sides, $x=-1$ Now plug in -1 for x in either of the equations: $y=-(-1)-4$ so $y=-3$