A line passes through the points (–17, –11) and (12, 18). What is its equation in slope-intercept form?

Question

needs to be in slope-intercept form

Answer 1

First step is to calc the slope (m).

rise/run = (y₂ - y₁)/(x₂ - x₁) = [18 - (-11)]/[12 - (-17)]

18 + 11 = 29; 12 + 17 = 29, so slope is 29/29 = 1

Point-slope form: y - y₁ = m(x - x₁). Can use either of the given points for x₁ and y₁ but (12,18) would be easier in this case because they are positive.

y - 18 = 1(x - 12) y = x - 12 + 18 y = x + 6 in slope-intercept form. Can use the other point to check - should give same result.

Answer 2

Start with two-point form

(y - (-11)) / (x - (-17)) = (18 - (-11)) / (12 - (-17))