Question

What is the equation of the line that passes through the point (-1,-5) and has a slope of -3

Answer 1

y = -3x + -4

Explanation:

y = mx + b

to find the y-intercept we need to add or subtract (in this case it's add) a number to x to get to 0.

x = -1.

to get to 0, you need to add one

do that same thing to y

`(-1, -5) + (1, 1) = (0, -4)` therefore the y-intercept (or b) is negative 4.

Answer 2

y = - 3x - 8

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - 3 , then

y = - 3x + c ← is the partial equation

To find c substitute (- 1, - 5) into the partial equation

- 5 = 3 + c ⇒ c = - 5 - 3 = - 8

y = - 3x - 8 ← equation of line