When 5a2b+10b2c2−21ab+32 is subtracted from 50−20b2c2−4bc−ac−5ab, we get
The correct option is B: 18−30b2c2−4bc−ac+16ab−5a2b
We have
(50−20b2c2−4bc−ac−5ab)−(5a2b+10b2c2−21ab+32)
=50−20b2c2−4bc−ac−5ab−5a2b−10b2c2+21ab−32
=50−32−20b2c2−10b2c2−ac−4bc−5a2b+21ab−5ab
=18−30b2c2−ac−4bc−5a2b+16ab
=18−30b2c2−4bc−ac+16ab−5a2b