Question

Resolvero por solucion cuadratica 18=6x+x(x-13)

Answer 1

$<var>18=6x+x(x+3);\ \ \ \ \ 18=6x+x^2+3x;\ \ \ \ \ \ 18=x^2+9x</var>$

 

$<var>0=x^2+9x-18</var>$

 

Usando:$<var>\frac{-b+-\sqrt{b^2-4.a.c}}{2a}</var>$

 

$<var>\frac{-9+-\sqrt{(9)^2-4(1)(-18)}}{2(1)}=\frac{-9+-\sqrt{153}}{2}</var>$

 

$<var>x_{1}=\frac{-9+\sqrt{153}}{2}\ \ \ \ \ y \ \ \ \ x_{2}=\frac{-9-\sqrt{153}}{2} </var>$

 

Exito.