Question

What is an equation of the line that passes through the points (−2,−1) and (4,8)?

Answer 1

`m = (8 - ( - 1))/(4 - ( - 2)) = (9)/(6) = (3)/(2)`

`y - 8 = (3)/(2) (x - 4)`

`y - 8 = (3)/(2) x - 6`

`y = (3)/(2) x + 2`

`2y = 3x + 4`

`- 3x + 2y = 4`

`3x - 2y = - 4`

Point-slope form:

y - 8 = (3/2)(x - 4)

Slope-intercept form:

y = (3/2)x + 2

Standard form:

3x - 2y = -4

Answer 2

y = 3x/2 + 2

Explanation:

slope = m = (-1 - 8)/(-2 - 4) = -9/(-6) = 3/2

y = mx + b

y = 3/2 x + b

point: (4, 8)

8 = 3/2 × 4 + b

b = 2

y = 3/2 x + 2

y = 3x/2 + 2