Question

Write the equation of the line between the two-points.
Points (-2,15) and (3,-20)

Answer 1

y = - 7x + 1

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) )`

let (x₁, y₁ ) = (- 2, 15 ) and (x₂, y₂ ) = (3, - 20 )

substitute these values into the formula for m

m =
`(-20-15)/(3-(-2))` =
`(-35)/(3+2)` =
`(-35)/(5)` = - 7 , then

y = - 7x + c ← is the partial equation

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

using (- 2, 15 ) for x and y

15 = - 7(-2) + c = 14 + c ( subtract 14 from both sides )

1 = c

y = - 7x + 1 ← equation of line