Question

The points (-7,3) and (-3,r) lie on a line with slope 4 . Find the missing coordinate r.

Answer 1

r = 19

Explanation:

calculate the slope using the slope formula and equate to 4

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

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

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

`(r-3)/(4)` = 4 ( multiply both sides by 4 )

r - 3 = 16 ( add 3 to both sides )

r = 19