Answer:
y = 9x - 14
Step-by-step explanation:
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y-intercept )
to calculate m use the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = (2, 4) and (x₂, y₂ ) = (1, - 5)
m = [tex]\frac{-5-4}{1-2}[/tex] = [tex]\frac{-9}{-1}[/tex] = 9, hence
y = 9x + c ← is the partial equation
to find c substitute either of the 2 points into the partial equation
using (2, 4 ), then
4 = 18 + c ⇒ c = 4 - 18 = - 14
y = 9x - 14 ← equation in slope- intercept form
