Question

Utilizando baskara resolva x² -4x -5 =0

Answer 1

Resposta:

$x'=-1$

$x''=5$

Explicação passo a passo:

$x^{2} -4x - 5=0$

$Para$ $ax^{2} +bx+c=0$$a=1,b=-4,c=-5$

$x=\frac{-b\pm\sqrt{b^{2} -4ac} }{2a}$

$a=1,b=-4,c=-5$

$x=\frac{-(-4)\pm\sqrt{(-4)^{2} -4\times 1 \times (-5)} }{2\times 1}$

$x=\frac{4\pm\sqrt{16 -4 \times (-5)} }{2}$

$x=\frac{4\pm\sqrt{16 +20} }{2}$

$x=\frac{4\pm\sqrt{36} }{2}$

$x=\frac{4\pm\sqrt{6^{2} } }{2}$

$x=\frac{4\pm6 }{2}$

$x=2\pm3$

$x'=2-3$

$x'=-1$

$x''=2+3$

$x''=5$