Question

Please write the slope-intercept form for this: A line goes through the points (5,18) and (-3,-14)

Answer 1

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 = $\frac{(- 14 - 18)}{( - 3 - 5)}$ = $\frac{- 32}{- 8}$ = 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