Point slope formula

Question

Find the point-slope equation for the line that passes through the points (-8, -32) and (3, 1). Use the first point in your equation.

Answer 1

m = (1 - (-32))/(3 - (-8)) = 33/11 = 3

y - y₁ = m(x - x₁)

y - (-32) = 3(x - (-8))

y + 32 = 3(x + 8)

Answer 2

The point-slope form of a line is y - y₁ = m(x - x₁) where the point that the line goes through is (x₁, y₁) and where "m" is the slope.

To find the slope, we use m = (y₂ - y₁)/(x₂ - x₁) and, in this case that's m = (1 - -32)/(3 - -8) = (1 + 32)/(3 + 8) = 33/11 = 3

So, using y - y₁ = m(x - x₁) and plugging in m = 3 and (x₁, y₁) as (-8, -32), we get:

y - -32 = 3(x - -8)

y + 32 = 3(x + 8)