If 5√5 x³ + 2√2y³ = (Ax + √2y) (Bx² + 2y² + Cxy), then the value of (A² + B² - C²) is?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 20.
Trick:
(√5x + √2y)³ = (√5x + √2y)(5x² +2y² -10xy)
On comparing we get
A = √5, B = 5, C = -√10
A² + B² - C² = 5 + 25 -10
= 20