Question

3x^2+9x-120=0 determine suas raízes
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Answer 1

Olá!

$\dfrac{-b\pm\sqrt{b^{2}-4\cdot a\cdot c} }{2\cdot a}~~~\to~~~\dfrac{-9\pm\sqrt{9^{2}-4\cdot 3\cdot (-120)} }{2\cdot 3}~~~\to ~~~\dfrac{-9\pm\sqrt{1521} }{6} ~~~\to ~~~\dfrac{-9\pm39}{6} \\ \\ \\ \\ \boxed{x'=5~~~e~~~x''=-8}$

:)