Question

Formula general
x2+2x-80

Answer 1

RESOLUCIÓN :


POR FORMULA GENERAL

$ax^2+bx+c=0\mathrm{\: \\ \\ \boxed{\\ \\ \boxed{x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}}} }}$

$x^{2} +2x-80 a=1,\:b=2,\:c=-80 x_{1,\:2}=\frac{-2\pm \sqrt{2^2-4\cdot \:1\left(-80\right)}}{2\cdot \:1}$

$x_{1} =\frac{-2+\sqrt{2^2-4\cdot \:1\left(-80\right)}}{2\cdot \:1}$

$=\frac{-2+\sqrt{324}}{2}$

$=\frac{-2+18}{2} =8$


$x_{2} =\frac{-2-\sqrt{2^2-4\cdot \:1\left(-80\right)}}{2\cdot \:1}$

$=\frac{-2-\sqrt{324}}{2}$

$=\frac{-2-18}{2}$


$=-\frac{20}{2} =-10$


RESPUESTA:   $\\ \\ \boxed{ x_{1} =8,\: x_{2} =-10}}$