Question

Writing the Equation of a Line Given Two Points
Use slope-intercept form, y = mx + b to find the equation of the line that passes through the points (−6, 1) and (3, 4).
y = –3x + 5
y = 3x – 5
y = one-third x + 3
y = negative one-third x + 5

Answer 1

Find the slope: m = (4 − 1)/(3 − (−6)) = 3/9 = 1/3.
Use y = mx + b with (−6, 1): 1 = (1/3)(−6) + b ⇒ 1 = −2 + b ⇒ b = 3.
So the equation is y = (1/3)x + 3 (y = one-third x + 3).