If the endpoint is (3/2, 1 1/2), and the midpoint is (2/5, -8/5) what is the other endpoint

The answer to your question is  ( -7/10, -4 7/10)

Step-by-step explanation:

Data

Enpoint (3/2, 1 1/2)                  x1 = 3/2     y1 = 1 1/2

Midpoint (2/5, -8/5)                xm = 2/5    ym = -8/5

Entpoint 2 ( x, y)

Formula

Xm = (x1 + x2)/2    Solve for x2    x2 = 2xm - x1

Ym = (y1 + y2)/2     Solve for y2   y2 = 2ym - y1

Substitution

                  x2 = 2(2/5) - 3/2

                  x2 = 4/5 - 3/2

                  x2 = (8 - 15)/10

                 x2 = -7/10

                  y2 = 2(-8/5) - 1 1/2

                 y2 = -16/5 - 3/2

                 y2 = (-32 - 15) / 10

                y2 = -47/10 = -4 7/10