The line that is given has a slope of 2, since it fits the form y = mx + b, where m is slope. Parallel lines have the same slope, so we want the slope of our line to be 2 as well. There are two common methods from here.
Method #1: Point-Slope Form
The point (-1, -3) can be labeled as (x1, y1). Plug x1, y1, and m into point-slope form: y - y1 = m(x - x1)
y - (-3) = 2(x - (-1))
y + 3 = 2(x + 1)
We need to solve for y so that we have slope-intercept form as required. Distribute, then subtract 3 from both sides.
y + 3 = 2x + 2
y = 2x - 1 is the answer
Method #2: Slope-Intercept Form
The point (-1, -3) can be used as (x, y) in the equation y = mx + b. Plug in and solve for b by adding 2 to both sides:
-3 = 2(-1) + b
-3 = -2 + b
-1 = b
We can now plug m and b into slope-intercept form: y = 2x - 1
