Of the five points (3, 10), (6, 20), (12, 35), (18, 40) and (20, 50), what is the sum of the -coordinates of the points that lie in the region above the line y = 2x + 7 in the coordinate plane?
A point lies above \(y=2x+7\) if its y -coordinate is greater than 2 times its x-coordinate plus 7. Checking the given points, we find that (6,20), (12,3), and (20,50) satisfy this condition. The sum of the x-coordinates of these points is \(6+12+20=\boxed{38}\).
