If x + y = 14; x3 + y3 = 1064, then the value of (x – y)2 is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 46.
| Understanding | Application |
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(x3 + y3) = (x + y)( x2 + y2 - xy) ( x - y )2 = ( x2 + y2 - 2xy) |
(x3 + y3) = (x + y)( x2 + y2 - xy) = (x + y)( x2 + y2 - xy + xy - xy ) = (x + y)( x2 + y2 - 2xy + xy) 1064 = 14 { (x - y)2 + xy} 76 = (x - y)2 + xy =(x - y)2 +30 (x - y)2 = 76 - 30 = 46 |