(r,-5) and (3,8) m=26/8

Question

solve for the missing x1 coordinate. use slope intercept for y=y2-y1 / x2-x1

Answer 1

(-5 - 8)/(r - 3) = 26/8

Cross multiply.

8(-13) = 26(r - 3)

-104 = 26r - 78

26r = -26

r = -1