Question

Find the other endpoint. Endpoint:(-1, 9), midpoint: (-9, -10)

Answer 1

from -1 to -9 is left 8, 8 more to the left is -17
from 9 to -10 is 19 down, 19 more is -29
your point should be (-17,-29)

Answer 2

i mean using the midpoint formula though

Answer 3

then solve
\[\frac{a-1}{2}=-9, \frac{b+9}{2}=-10\] for a and b