Question 242795
Through (1,-8), perpendicular to 
-7x-4y=25
-4y=7x+25
y=-7x/4+25/-4
y=-7x/4-25/4 slope=-7/4.
A perpendicular line will have a slope = to the negative inverse or 4/7
-8=4/7*1+b
-8=4/7+b
b=-8-4/7
b=-56/7-4/7
b=-60/7 the y intercept.
y=4x/7-60/7 
{{{ graph( 300, 200, -6, 25, -15, 10, 4x/7 -60/7) }}} (graph 300x200 pixels, x from -6 to 25, y from -15 to 10, 4x/7 -60/7).