Question

помогите пожалуйста!! решение неравенства -x^2+7>0​

Answer 1

$\displaystyle\bf\\-x^{2} +7 > 0\\\\x^{2} -7 < 0\\\\x^{2} -(\sqrt{7} )^{2} < 0\\\\(x-\sqrt{7} )\cdot(x+\sqrt{7} ) < 0\\\\\\+ + + + +(-\sqrt{7})- - - - - (\sqrt{7} )+ + + + + \\\\\\Otvet \ : \ x\in(-\sqrt{7} \ ; \ \sqrt{7} \ )$