Question

cum se rezolva
$4(x { }^{2} - 5) + (x - 3)(x + 3) - (x - 5) {}^{2}$
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Answer 1

4(x² - 5) + (x - 3)(x + 3) - (x - 5)² =

= 4x² - 20 + x² - 9 - x² + 10x - 25

= 4x² + 10x - 54