Parallel lines all have the same slope. So you have the same number in front of the x as you do on the given equation.
This is what you know so far
y = 1/2 x + _____
Now you use the point to determine what _____ is.
The general equation for a line is y = mx + b. We know that m = 1/2. We need the point to solve for b
x = 4 ; y = 5 Substitute these values into the general equation.
5 = 1/2(4) + b Combine 1/2 and 4
5 = 2 + b Subtract 2 from both sides.
5 - 2 = b
b = 3
So the answer is y = 1/2 x + 3