Question

Me ajudem por favor nessa equação do segundo grau!
x2+20x+105=6

Answer 1

$x^{2}+20x+105=6 \\ x^{2}+20x+105-6=0 \\ x^{2}+20x+99 \\ \\ x= \frac{-b+- \sqrt{b^{2}-4*a*c } }{2*a} = \frac{-20+- \sqrt{20^{2} -4*1*99} }{2} = \frac{-20+- \sqrt{400-396} }{2} = \frac{-20+- \sqrt{4} }{2} \\ \\ = \frac{-20+-2}{2} \\ \\ x_{1} = \frac{-20+4}{2} = \frac{-16}{2} =-8 \\ \\ x_{2} = \frac{-20-4}{2} = \frac{-24}{2} =-12$

S = { -12 , -8 }