Verified answer

[tex]3x^2-5x-36=0\\\frac{3x^2}{3} -\frac{5x}{3} -\frac{36}{5} =0\\= > x^2-\frac{5}{3} x-7,2=0\\\left \{ {{x_{1} *x_{2} =c} \atop {x_{1} +x_{2} =-b}} \right. \left \{ {{x_{1} *x_{2}=-7,2} \atop {x_{1} +x_{2} = \frac{5}{3} }} \right.\\\left \{ {{x_{1}=\frac{25-7\sqrt{145} }{30} } \atop {x_{2}=\frac{25+7\sqrt{145} }{30}}} \right.[/tex]