I'm assuming the equation is y = 1/2x + 2
The equation you will be using is:
y = mx + b
For the equation to be parallel to the given/first equation, the slopes have to be the same. The first equation's slope is 1/2, so the second equation's slope is also 1/2.
y = 1/2x + b
To find "b", you plug in the point (0, -7) into the equation.
y= 1/2x + b
-7 = 1/2(0) + b
-7 = b
Now that you know b, you can plug it in. Your equation is:
y = 1/2x - 7