Question

The points (4, -11) and (8, r) lie on a line with slope 2. Find the missing coordinate r.

Answer 1

The answer to your question is r = -3

Explanation:

Data

A (4, -11)

B (8, r)

slope = m = 2

r = ?

Process

1.- Use the slope equation to find the coordinate r.

Formula

`m = (y2 - y1)/(x2 - x1)`

Substitution

`m = (r + 11)/(8 - 4)` = 2

2.- Simplify

`(r + 11)/(4) = 2`

3.- Solve for r

Multiply both sides by 4

`(4(r + 11))/(4) = 2(4)`

Simplify

r + 11 = 8

Subtract 11 in both sides

r + 11 - 11 = 8 - 11

Simplify

r = -3