SOLUTION: how do i find the value of r in this equation. A line passes through the point r,5 and -2,r and has a slope of -2/9

Question 1127854: how do i find the value of r in this equation.
A line passes through the point r,5 and -2,r and has a slope of -2/9

Answer by ikleyn(52765) (Show Source): You can put this solution on YOUR website!
.

According to the definition of the slope, it is


    m = ,


which gives you an equation


     = ,


or, equivalently,


     = .


Solve it for "r".


    9*(r-5) = 2*(2+r)

    9r - 45 = 4 + 2r

    9r - 2r = 4 + 45

    7r = 49    ====>  r = 49/7 = 7.     ANSWER

Solved.

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