Question

Which is the equation of a line with the slope of -2 that passes through the point (-2,0)

Answer 1

The equation of a line is y = mx + b (m is the slope; b is the y-intercept)

We are given the slope of -2 so...

y = -2x + b

We must determine b. Since they give us a point, we can sub in the x and y coords (-2,0)

0 = -2(-2) + b
0 = 2 + b
[Subtract 2 from both sides]
0-2=2-2+b
-2=b

Now, go back to the original equation (before adding coordinates in) and input b.

y = -2x-2

Answer 2

y = -2x - 4

-2x is the slope and -4 is the y intercept.