Question

Fie a multimea solutiilor reale ale ecuatiei 3x^{2}+5x-2=0.Determina multimea A\{-3;1pe3}.

Answer 1

[tex]3x^2+5x-2=0\\ \Delta=25+24=49\Rightarrow \sqrt{\Delta}=7\\ x_1=\dfrac{-5+7}{6}=\dfrac{1}{3}\\ x_2=\dfrac{-5-7}{6}=-2\\ A=\left\{\dfrac{1}{3},-2\right\}\\ A-\left\{-3;\dfrac{1}{3}\right\}=\{-2\}[/tex]