Question

The points (-3, -3) and (5, r) lie on a line with slope 3/2
Find the missing coordinate r.

Answer 1

The missing coordinate
`r` is 9.

Explanation:

Given the points
`P(x,y) = (-3,-3)` and
`Q(x,y) = (5,r)`, the slope of a line passing the two points (
`m_(PQ)`) is determined by equation of secant line:

`m_(PQ) = (y_(Q)-y_(P))/(x_(Q)-x_(P))` (1)

`m_(PQ) = (r-(-3))/(5-(-3))`

If we know that
`m_(PQ) = (3)/(2)`, then the value of
`r` is:

`(3)/(2) = (r+3)/(8)`

`12 = r + 3`

`r = 9`

The missing coordinate
`r` is 9.