What must be added to algebraic expression 2a2-7ab+5b2 to get a2+4ab-3b2?
To obtain the required expression, we have to subtract 2a2-7ab+5b2froma2+4ab-3b2
a2+4ab-3b22a2-7ab+5b2-+-______________-a2+11ab-8b2_______________(changing the sign of each term)
Therefore, the required expression is -a2+11ab-8b2.
What must be subtracted from 3a2 − 6ab − 3b2 − 1 to get 4a2 − 7ab − 4b2 + 1?