0,x\in R\\\\(x-7)(x+7) \geq 0\\\\+ + + + +(-7)- - - - (7)+ + + + + \\\\x\in(-\infty,-7)U(7,+\infty)" alt="x^2(-x^2-49) \geq 49(-x^2-49)\\\\x^2(-x^2-49)-49(-x^2-49)\leq 0\\\\(-x^2-49)(x^2-49) \leq 0\\\\-(x^2+49)(x^2-49) \leq 0\\\\(x^2+49)(x-7)(x+7) \geq 0\\\\(x^2+49>0,x\in R\\\\(x-7)(x+7) \geq 0\\\\+ + + + +(-7)- - - - (7)+ + + + + \\\\x\in(-\infty,-7)U(7,+\infty)" align="absmiddle" class="latex-formula">