Question

Choose the equation below that represents the line passing through the point (−3, −1) with a slope of 4.
y − 1 = 4(x − 3)
y + 1 = 4(x + 3)
y − 3 = 4(x + 1)
y + 3 = 4(x − 1)

Answer 1

Are you familiar with the slope intercept form of a line? y = mx + b?

Answer 2

What you do in this type of a situation is to plug in what they give you and solve for b, the y intercept, and the go back into the general form, plug the slope back in that they give you to be 4 and the b that you solved for, and there you have it!

Answer 3

In the point they gave you, y is -1 and x is -3, and you have a slope of 4. Plug these in like this:
y = mx + b
-1 = 4(-3) + b and solve for b.

Answer 4

When you get a solution for b, plug it back in like this:
y = 4x + ____

Answer 5

It could also be a negative solution, and in that case, you'll have y = 4x - ____

Answer 6

Oh I see you need it in point slope. No worries. That's even easier!

Answer 7

This is point-slope form for a general line:
\[(y-y _{1})=m(x-x _{1})\]

Answer 8

Again you have a y value from the point of -1 and an x value of -3, with a slope of 4. Just plug in the numbers.

Answer 9

Keep in mind the rules of subtracting negative numbers from each other.