Question

Help me solve (-9,8) and perpendicular to the line whose equation is y=5/6x+7/6

Answer 1

your given line has slope 5/6
so all perpendicular lines have slope -6/5
Now you have a point and a slope, so just use the point-slope form for your new line.

Answer 2

m1 = 5/6.
m2 = -6/5.

P(-9, 8).
Y = m2*x + b,
8 = (-6/5)(-9) + b,
b = ?.

Eq: m2*x + b.