Answer:
XY = 10
Explanation:
By the definition of midpoint, XM would be equal to MY, so we can set both equations equal to each other;
XM = MY
8 - t = 5t - 10
=> Now add "t" to both sides of "="
8 = 6t - 10
=> add 10 from each side;
18 = 6t
=> Finally divide 6 on each side
3 = t
Now that we have the value for t, we can substitute 3 in place of "t" in any of the equation above and solve, when we have the answer, multiply it by 2 to get the value for XY.
=> 8 - 3
=> 5
=> XY = 5 * 2
=> XY = 10
Hope this helps!