Precalculus (6th Edition) Blitzer

point-slope form: $y+9=7(x-5)$ general form: $7x-y-44=0$
Step 1. As the line is perpendicular to the line $x+7y-12=0$, we have its slope $m=7$ Step 2. As the line passes through the point $(5,-9)$, we can write the line equation in point-slope form as $y+9=7(x-5)$ Step 3. The above equation can be rewritten in general form as $y+9=7x-35$ or $7x-y-44=0$