How do you find the value of r?

Question

(2,8),(r,-4) m=-3

i have no idea on how do to this, my teacher was not clear

Answer 1

Hello, thank you for taking the time to post your question!

The underlying slope equation that you want to use here is m=(y2​−y1​)/(x2​−x1​) … for this set of values that means −3=(−4−8)/(r−2)

Solving that algebraically for the value of “r” yields

−3=−12/(r−2)

−3∗(r−2)=−12

r−2=−12/−3

r−2=4

r=6

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

Slope= (y₂-y₁)/(x₂-x₁)

-3=(-4-8)/(r-2)

-3(r-2)=(-4-8)

-3(r-2)=-12

r-2=-12/-3

r-2=4

r=4+2

r=6