What is (x^2 - xy + y^2) equal to ?
For the next two (02) items that follow : Let x = \frac{\sqrt{6} + \sqrt{5}}{\sqrt{6} - \sqrt{5}} and y = \frac{\sqrt{6} - \sqrt{5}}{\sqrt{6} + \sqrt{5}}
- A. 487
- B. 483
- C. 481 ✓
- D. 480
Correct Answer: C. 481
Explanation
We know x+y = 22 and xy = 1. The expression x^2 - xy + y^2 = (x+y)^2 - 3xy = 22^2 - 3(1) = 484 - 3 = 481.
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