Resposta:
[tex]x1 = \frac{3-\sqrt{33} }{2} \\\\x2 = \frac{3+\sqrt{33} }{2}[/tex]
Explicação passo-a-passo:
[tex]-x^2+3x+6=0\\\\ a = -1, b = 3, c = 6\\ \\ x1 = \frac{-b+\sqrt{b^2-4*a*c}}{2*a} \\\\ x1 = \frac{-3+\sqrt{3^2-4*(-1)*6}}{2*(-1)}\\\\x1 = \frac{3-\sqrt{33} }{2} \\ ---------------------- \\\\ x2 = \frac{-b-\sqrt{b^2-4*a*c}}{2*a} \\\\ x2 = \frac{-3-\sqrt{3^2-4*(-1)*6}}{2*(-1)}\\\\ x2 = \frac{3+\sqrt{33} }{2}[/tex]
