Question

Find an equation of the line L.
L is perpendicular to y=3x
(-1,-3)

Answer 1

Find an equation of the Line L.
L is parallel to y=2x
(-2,-7)

Answer 2

slope of first one = 3
slope of perpendicular = -1/3
so
y = -(1/3) x + b
if x = -1, y = -3
-3 = -(1/3)(-3) + b
-3 = 1+b
b = -4
so
y = -x/3 - 4
=======================
y = 2 x slope = 2
y = 2 x + b
-7 = 2(-2) + b
-7 = -4 + b
b = -3
so
y = 2 x - 3