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 Question from Anne, a student: Se x e y são números reais distintos, então: a) (x² + y²) / (x - y) = x + y b) (x² + y²) / (x - y) = x - y c) (x² - y²) / (x - y) = x + y d) (x² - y²) / (x - y) = x - y e) Nenhuma das alternativas anteriores é verdadeira.

Hi Anne,

If

$\frac{a}{x - y} = x + y$

then

$(x - y) \frac{a}{x - y} =(x - y)(x + y)$

or

$a = (x - y)(x + y).$

Expand the right side. Which of a), b), c) and d) is true?

Harley

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