Question

Write an equation in slope-intercept form that passes through (-8, -1) and (-7,3).

Answer 1

y = 4x + 31

Explanation:

the equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

calculate m using the slope formula

m =
`(y_(2)-y_(1) )/(x_(2)-x_(1) )`

with (x₁, y₁ ) = (- 8, - 1 ) and (x₂, y₂ ) = (- 7, 3 )

m =
`(3-(-1))/(-7-(-8))` =
`(3+1)/(-7+8)` =
`(4)/(1)` = 4 , then

y = 4x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (- 7, 3 ) , then

3 = - 28 + c ⇒ c = 3 + 28 = 31

y = 4x + 31 ← equation of line