A parallel line will have the same slope as the original. The slope intercept stanfdard form of a straight line is y=mx+b, where m is the slope and b is the y intercept.
Since our parallel line must have the same slope as the original (1/2), it will have the form y = (1/2)x+b. The thing that will make it different is b, the y intercept. To find b, just enter the one point we know is on the new line (3,5).
y = (1/2)*x + b
5 = (1/2)*(3)+b
b = 3.5
So the new line becomes y = (1/2)x+ 3.5