Please answer and i have to show work

B

Step-by-step explanation:

Calculate the slope m using the slope formula and equate to

m =

with (x₁, y₁ ) = (3, 2) and (x₂, y₂ ) = (r, - 4)

m = = , then equating gives

= ( cross- multiply )

3(r - 3) = - 12 ( divide both sides by 3 )

r - 3 = - 4 ( add 3 to both sides )

r = - 1 → B

answer:

a=9

step-by-step explanation: lmk if you need a explanation