[tex]\displaystyle x^2+5x-6=0 \\ \\ \Delta=b^2-4ac\\ \Delta=5^2-4\cdot1\cdot(-6) \\ \Delta=25+24=49 \\ \\ X_{1,2}= \frac{-b \pm \sqrt{\Delta} }{2a} \\ \\ X_1= \frac{-5-7}{2} = -\frac{12}{2} =-6 \\ \\ X_2= \frac{-5+7}{2}= \frac{2}{2} =1 \\ \\ \text{The solution set: -6 and 1}[/tex]
