Which equation passes through the point (2,4) and is parallel to the line x-2y=6

A line parallel to x-2y=6 has which slope?  Solving for y, -2y = 6 - x, and 
m = -1  /  -2,  or   1/2.

Then the slope-intercept formula, y = mx + b, becomes  4 = (1/2)(2) + b, and b is 3.  Thus, the equation of this line is y = (1/2)x + 3.

Check:  does the point (2,4) satisfy this equation?  Is   4 = (1/2)(2) + 3 true?  YES.