The midpoint of a segment can be found using the formulas for a directed line segment, x = (x2 – x1) + x1 and y = (y2 – y1) + y1. When using these formulas to find a midpoint, which is true? a = 1 and b = 2 a = 2 and b = 1 a = 1 and a + b = 2 a = 2 and a + b = 2