y = 4x - 2
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 )
let ( x₁, y₁ ) = (5, 18) and (x₂, y₂ ) = ( - 3, - 14 )
m =
=
= 4
the partial equation is y = 4x + c
to find c substitute either of the 2 given points into the partial equation
using (5 , 18) then 18 = 20 + c ⇒ c = 18 - 20 = - 2
y = 4x - 2 is the equation in slope- intercept form