Question

What is the equation of the line that passes through the point (-3, -1) and has a slope of -4 ?

y = -4x + 13
y = -4x + 7
y = -4x -7
y = -4x - 13

Answer 1

y = - 4x - 13

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 = - 4, thus

y = - 4x ++ c ← is the partial equation

To find c substitute (- 3, - 1) into the partial equation

- 1 = 12 + c ⇒ c = - 1 - 12 = - 13

y = - 4x - 13 ← equation of line