Answer:
p = - 2
Step-by-step explanation:
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (- 1, - 3) and (x₂, y₂ ) = (3, 7)
m = [tex]\frac{7-(-3)}{3-(-1)}[/tex] = [tex]\frac{7+3}{3+1}[/tex] = [tex]\frac{10}{4}[/tex] = [tex]\frac{5}{2}[/tex]
Parallel lines have equal slopes
Calculate the slope of the other 2 points and equate to [tex]\frac{5}{2}[/tex]
with (x₁, y₁ ) = (3, p) and (x₂, y₂ ) = (7, - 4p)
m = [tex]\frac{-4p-p}{7-3}[/tex] = [tex]\frac{-5p}{4}[/tex] = [tex]\frac{5}{2}[/tex] ( cross- multiply )
- 10p = 20 ( divide both sides by - 10 )
p = - 2
