Answer:
y + 21 = - 4(x - 7)
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the line
Calculate m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (7, - 21) and (x₂, y₂ ) = (- 4, 23)
m = [tex]\frac{23+21}{-4-7}[/tex] = [tex]\frac{44}{-11}[/tex] = - 4
Using m = - 4 and (a, b) = (7, - 21), then
y - (- 21) = - 4(x - 7), that is
y + 21 = - 4(x - 7)
