Show that the statement is true. If DE has endpoints D(-1,8) and E(7,-2), then the midpoint M of DE lies in Quadrant I.
D. M lies in (select)
since the x-coordinate is (select)
The midpoint M is
and the y-coordinate is (select)

midpoint = (x1 + x2) / 2, (y1 + y2)/2

(-2,1)x1 = -2 and y1 = 1

(4,-1)...x2 = 4 and y2 = -1

time to sub

m = (-2 + 4) / 2 , (1 + (-1) / 2

m = (2/2), (0/2)

m = (1,0) <==

y = -x + 1(1,0)...x = 1 and y = 0

0 = -1 + 1

0 = 0 (correct)

so the midpoint  M (1,0) lies on the line since its coordinates satisfy the equation <===

Step-by-step explanation:

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.