Autotrophic organisms are able to take inorganic molecules and transform them into organic nourishment by using light or chemical energy. why are autotrophic organisms considered essential to all other life on earth?

They are the primary producers at the base of the food chain.

Scale factor: 1/2

B (-8, -2)

Since your scale factor is 1/2 you would divide each of your coordinates by 2.
X- Coordinate: -8 divided by 2 would be -4
Y- coordinate: -2 divided by 2 would be -1

New coordinate: B (-4, -1) <That is your answer

HOPE THIS HELPS! ^_^