Sangeetha Pulapaka
0


Calculate the slope

Take the slope formula and plug in the slope and both pairs of (xy) coordinates. Then solve for r.

                                  slope  =\frac{y_{2}-y_{1}}{x_{2}-x_{1}}

Plugging in slope m = -1 and x_{1} = 2, y_{1} = r, x_{2}= -1, y_{2} = 7

-1 = \frac{7-r}{-1-2}


-1(-1 -2) = 7 - r

3 = 7 - r

r = 4