The simplified form of (x + 2y)3 + (x - 2y)3 is :
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 2x3 + 24xy2
Formula used:
(x + y)3 = x3 + y3 + 3xy(x + y) ---- (1)
(x - y)3 = x3 - y3 - 3xy(x - y) ---- (2)
Calculations:
⇒ (x + 2y)3 + (x - 2y)3
Using equation (1) and (2)
⇒ x3 + 8y3 + 6xy(x + 2y) + x3 - 8y3 - 6xy(x - 2y)
⇒ x3 + 8y3 + 6x2y + 12xy2 + x3 - 8y3 - 6x2y + 12xy2
⇒ 2x3 + 24xy2