Question

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

Answer 1

Answer:

r = -13

Step-by-step explanation:

The formula of a slope:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

We have the slope m = 2/3 and the points (-4, 3) and (r, -3). Substitute:

$\dfrac{-3-3}{r-(-4)}=\dfrac{2}{3}$

$\dfrac{-6}{r+4}=\dfrac{2}{3}$        cross multiply

$2(r+4)=(-6)(3)$        divdide both sides by 2

$r+4=(-3)(3)$

$r+4=-9$       subtract 4 from both sides

$\boxed{r=-13}$