What do we need to find the equation of a line?
1) A point
2) A slope
The problem gives the point: (-3,-3)
It has the same slope as the line x-2y=-7 (because they are parallel).
Now, just figure out the slope of that line:
x-2y=-7
x+7-2y=0
x+7=2y
y=(1/2)x + 3.5
The slope of this line is that coefficient in front of x: 1/2
Now, the line you are looking for has the point (-3,-3) and the slope 1/2. Using the point slope form of a line we get:
y-(-3) = (1/2)(x-(-3))
y+3 = (1/2)(x+3)
This is an acceptable answer in point slope form, or you can take it into slope intercept form (y=mx+b):
y+3 = (1/2)(x+3)
y+3 = (1/2)x + 1.5
y = (1/2)x - 1.5
