Question

x2-4x-5 por la fórmula general porfas ​

Answer 1

Explicación paso a paso:

$\frac{- b \frac{ + }{ - } \sqrt{ {b}^{2} - 4ac} }{2a} = \frac{- ( - 4) \frac{ + }{ } \sqrt{ {(4)}^{2} - 4(1)( - 5)} }{2(1)} = \frac{4 \frac{ + }{ } \sqrt{ 16 + 20} }{2} = \frac{4 \frac{ + }{} \sqrt{36} }{2} = \frac{4 \frac{ + }{} 6}{2} \\ x1 = \frac{4 + 6}{2} = \frac{10}{2} = 5 \\ x2 = \frac{4 - 6}{2} = \frac{ - 2}{2} = - 1$

COMPROBACIÓN

${x}^{2} - 4x - 5 = 0 \\ {(5)}^{2} - 4(5) - 5 = 0 \\ 25 - 20 - 5 = 0 \\ 25 - 25 = 0 \\ 0 = 0$

${x}^{2} - 4x - 5 = 0 \\ {( - 1)}^{2} - 4( - 1) - 5 = 0 \\ 1 + 4 - 5 = 0 \\ 5 - 5 = 0 \\ 0 = 0$