## If a line passes through the points (-5,-4) and (3,-1), the equation of the line is?

Question

If a line passes through the points (-5,-4) and (3,-1), the equation of the line is?

0

1. y = x – 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 ) = (- 5, – 4 ) and (x₂, y₂ ) = (3 , – 1 )

m = = the partial equation is y = x + c

to find c substitute either of the 2 points into the partial equation

using (3, – 1 ), then

– 1 = + c ⇒ c = – y = x – ← in slope-intercept form

2. answer: y = 1.5x – 5.5

explanation:

use y = mx +b to model your equation

(m = slope, b = y-intercept)

let’s start by finding slope

to find slope, subtract the y values over the x values.

– 4 – (-1) / – 5 – (-3)

solve and simplify.

-3 / -2

two negatives equals a positive, so convert into a decimal and remove the negative

you get 1.5.

now, plug the slope a y and x value into the equation to find b, the missing value.

-1 = 1.5(3) + b

-1 = 4.5 + b

-5.5= b

so, your equation is y = 1.5x – 5.5.