find the value of r

Question

find the value of r so that the line that passes through (5,-2) and (r, 4) has a slope of 3/2

Answer 1

Hi Christine,

The formula for slope is (y2-y1)/(x2-x1)

So [4 - (-2)] / [r - 5] = 3/2

6/(r-5) = 3/2

Cross multiply

6 * 2 = 3 ( r-5)

Distribute on right

12 = 3r - 15

add 15 to both sides

27 = 3r

divide both sides by 3

r = 9