Question

$\sqrt{x + 5} = x - 1$
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Answer 1

$\sqrt{x + 5} = x - 1 \\ x + 5 = {x}^{2} - 2x + 1 \\ x + 5 - {x}^{2} + 2x - 1 =0 \\ - {x}^{2} + 3x + 4 = 0 \\ {x}^{2} - 3x - 4 = 0 \\ d = ( - 3 {)}^{2} - 4 \times 1 \times ( - 4) = 25 \\ x = \frac{3 + 5}{2} = \frac{8}{2} = 4 \\ x = \frac{3 - 5}{2} = - \frac{2}{2} = - 1$