Question

The points (-9, r) and (-5, 13) lie on a line with the slope 2. Find the missing coordinate r.
.

Answer 1

\[\LARGE \frac{y_2-y_1}{x_2-x_1}=slope\]
\[\LARGE \frac{13-r}{-5--9}=slope\]
\[\LARGE \frac{13-r=?}{-5+9=?}=slope\]

Answer 2

13-r/4

Answer 3

13-r/4=slope
What should we subtract from 13 so that the slope will be 2?

Answer 4

4

Answer 5

13-r=4
13-4=?

Answer 6

9

Answer 7

Good so we get r=9
Because
13-9=4/2=2