What must be subtracted from x3 - 3x2y + 3xy2 - y3 to get x3 - y3?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. -3x2y + 3xy2.
(x3 - 3x2y + 3xy2 - y3) - (x3 - y3)
= x3 - 3x2y + 3xy2 - y3 - x3 + y3
= - 3x2y + 3xy2