Answer:
see explanation
Step-by-step explanation:
A
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = C(- 7, - 2) and (x₂, y₂ ) = D(- 4, 2)
m = [tex]\frac{2+2}{-4+7}[/tex] = [tex]\frac{4}{3}[/tex]
--------------------------------------
B
Parallel lines have equal slopes.
Calculate the slope of AB and equate to the slope of CD
(x₁, y₁ ) = A(4, y) and (x₂, y₂ ) = B(7, 4)
m = [tex]\frac{4-y}{7-4}[/tex], that is
= [tex]\frac{4-y}{3}[/tex] = [tex]\frac{4}{3}[/tex] ( cross- multiply )
3(4 - y) = 12 ( divide both sides by 3 )
4 - y = 4 ( subtract 4 from both sides )
- y = 0 ⇒ y = 0
