Решите уравнение x^2(x^2-4)=45 x^2(8-x^2)+9=0

[latex] x^{2} ( x^{2} -4)=45[/latex] [latex] x^{4} -4 x^{2} =45[/latex] [latex] x^{2} =t[/latex] [latex] t^{2} -4t-45=0[/latex] [latex]D= b^{2} -4ac=16+180=196[/latex] [latex] t_{1} = \frac{-b+ \sqrt{D} }{2a} = \frac{4+14}{2} =9[/latex] [latex] t_{2} = \frac{-b- \sqrt{D} }{2a} = \frac{4-14}{2}=-5[/latex] [latex]1) t_{1} =9[/latex]    [latex] x^{2} =9[/latex]    [latex]x=3[/latex]    [latex]x=-3[/latex] [latex]2) t_{2} =-5[/latex]    [latex] x^{2} =-5[/latex] - решения нет