5x^2/x^2-1+2x^2-2x-3=4x^2[tex]5x^{2}/{x^{2}-1}+2x^{2}/x^2-2x-3=4x^{2}-9x/x^{2}-4x+3[/tex]

помогите!!

5х^2/x^2-1+2x^2/x^2-2x-3=4x^2-9x/x^2-4x+3

 1/x^2-1/x-30=0

z^2-1/z^2+5z-6=0