Find the product of (a + b + 2c)(a2 + b2 + 4c2 - ab - 2bc - 2ca).
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e a3 + b3 + 8c3 - 6abc
⇒ (a + b + 2c)(a2 + b2 + 4c2 - ab - 2bc - 2ca)
As we know that, (a + b + c)(a2 + b2 + c2 - ab - bc - ac) = (a3 + b3 + c3 - 3abc)
⇒ (a + b + 2c)(a2 + b2 + (2c)2 - ab - 2c(b) - 2c(a))
⇒ (a3 + b3 + 8c2 - 6abc)