Question

Given endpoint P(1, -4) and midpoint M(5, -7), what is the coordinate of ENDPOINT Q? If needed, round to the nearest tenth.

Answer 1

Your subject is Math, not Class

You should have a definition or method for finding the midpoint
Let the missing endpoint be (x,y)

for the x:
(x+1)/2 = 5
x+1 = 10
x = 9

for the y:

you do it.