Question

Qual o valor da equação-2x²+3x+5=0?

Answer 1

Resposta:

$-2x^{2} +3x+5=0\\ \\ coeficientes:\\ a=-2\\ b=3\\ c=5\\ \\ delta=b^{2} -4.a.c\\ \\ delta=3^{2} -4.(-2).5\\ \\ delta=9-(-40)\\ \\ delta=9+40\\ \\ delta=49\\ \\ \\ x=\frac{-b+-\sqrt{delta} }{2.a} \\ \\ x=\frac{-3+-\sqrt{49} }{2.(-2)} \\ \\ x=\frac{-3+-7}{-4} \\ \\ x'=\frac{-3+7}{-4} =\frac{4}{-4} =-1\\ \\ x''=\frac{-3-7}{-4} =\frac{-10}{-4} =\frac{5}{2} \\ \\ S\left \{ {{-1;\frac{5}{2} } {}} \}$