Algebra: A Combined Approach (4th Edition)

We use the formula $y=mx+b$ $y=-5x+b$ now plug in $x=3$ and $y=-7$ to get b: -7 = -5(3) + b -7 = -15 + b b=8 $y=-5x+8$ and it must be written in standard form $Ax+By=C$, so rearrange: 5x + y = 8