[tex]x^{2} +6x-7\leq 0\\\\a=1 ~~\Rightarrow ~~a>0~~ramiona~~skierowane~~do~~gory\\\\a=1,~~b=6,~~c=-7\\\\\Delta=b^{2} -4ac\\\\\Delta=6^{2} -4\cdot 1\cdot (-7)=36+28=64\\\\\sqrt{\Delta} =\sqrt{64} =8\\\\x_{1} =\dfrac{-b-\sqrt{\Delta} }{2a} ~~\lor ~~x_{2} =\dfrac{-b+\sqrt{\Delta} }{2a}\\\\\\x_{1} =\dfrac{-6-8}{2}=\dfrac{-14}{2} =-7 ~~\lor~~x_{2} =\dfrac{-6+8}{2}=\dfrac{2}{2}=1\\\\x^{2} +6x-7\leq 0~~\Rightarrow ~~x\in <-7;1>[/tex]
