Hey there! :)
We're given the equation : y = 1/3x - 2 & coordinates : (-3, 5)
If we're looking for an equation for a perpendicular line, then we know that the slope of our new equation MUST be the negative reciprocal of the original slope. This means that you flip the slope and add or remove a negative. Example : slope = -2 ⇒ negative reciprocal slope = 1/2
Before using this information, we must first find the slope of our original equation.
Using slope-intercept form, which is : y=mx+b ; where m=slope, b=y-intercept
Ask yourself : which value is in the "m" spot and which value is in the "b" spot?
Using this, we now know that 1/3 is our slope, and -2 is our y-intervept.
So, our negative reciprocal is -3.
Use point-slope form to find the y-intercept, and coordinates (-3, 5)
Point-slope = y - y1 = m(x - x1)
y - 5 = -3(x - (-3))
Simplify.
y - 5 = -3(x + 3)
Simplify.
y - 5 = -3x - 9
Add 5 to both sides.
y = -3x + 4 ⇒ slope-intercept form
~Hope I helped! :)