Question

The points (−7,10) and (−r,1) lie on a line with slope 3/4. Find the missing coordinate r.

Answer 1

use slope formula:
\[\frac{ y_2-y_1 }{ x_2 -x_1}=slope\]

Answer 2

now substitute your points and solve:\[\frac{ 10-1 }{-7+r }=3/4\]

Answer 3

solve for r