Question

The points (3, 2) and (r, -2) lie
on a line with slope -2. Find the missing coordinate r.

Answer 1

you use formula (x1+y1) for ur first set of points and (x2+x2) for your second. then put them over eachother.

Answer 2

r = 5

Explanation:

calculate the slope m of the 2 given points and equate to - 2

using the slope formula

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

with (x₁, y₁ ) = (3, 2 ) and (x₂, y₂ ) = (r, - 2 )

m =
`(-2-2)/(r-3)` =
`(-4)/(r-3)`

equating to - 2 gives

`(-4)/(r-3)` = - 2 ( multiply both sides by r - 3 to clear the fraction )

- 4 = - 2(r - 3) ← divide both sides by - 2 )

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

5 = r