Question

помогитеее взав ра контрошкаа
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Answer 1

Объяснение:

$\frac{x {}^{4} + 3x {}^{2} - 4 }{x {}^{4} + 7x {}^{2} + 12 } = \frac{x {}^{4} + 4x {}^{2} - x {}^{2} - 4}{x {}^{4} + 4x {}^{2} + 3x {}^{2} + 12 } = \frac{x {}^{2} \times (x {}^{2} + 4) - (x {}^{2} + 4) }{x {}^{2} \times (x {}^{2} + 4) + 3(x {}^{2} + 4) } = \frac{(x {}^{2} + 4 ) \times (x {}^{2} - 1)}{(x {}^{2} + 4) \times (x {}^{2} + 3) } = \frac{x {}^{2} - 1 }{x {}^{2} + 3}$