If x² − y² = 255 and x + y = 17, find the value of (x − y).
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Correct answer: B
Explanation
Given:
x² − y² = 255, x + y = 17
According to the formula:
x² − y² = (x − y)(x + y)
(x − y)(x + y) = 255
(x − y)(17) = 255
x − y = 255 / 17 = 15