D²/dx(f(x}=x²-4/x²+4)=f(x)+24/x∧4=2 (ВТОРАЯ f c двумя штрихами)
х∧4f(x)=2x∧4-24 (f c двумя штрихами)
x∧4f(x)+24/x∧4=2
<span>(y/x-y + x/x+y) : (1/x^2 + 1/ y^2) - y^4/ x^2-y^2 = (y(x+y)+x(x-y)/(x-y)(x+y))/(x^2+y^2/x^2y^2)-y^4/(x-y)(x+y) = (xy+y^2+x^2-xy/(x-y)(x+y))/(x^2+y^2/x^2y^2)-y^4(x-y)(x+y) = (x^2+y^2/(x-y)(x+y))/(x^2+y^2/x^2y^2)-y^4(x-y)(x+y) = (x^2+y^2)(x^2y^2)/(x^2+y^2)(x-y)(x+y)-y^4/(x-y)(x+y) = x^2y^2/(x-y)(x+y)-y^4/(x-y)(x+y) = x^2y^2-y^4/(x-y)(x+y) = y^2(x^2-y^2)/(x-y)(x+y) = y^2(x-y)(x+y)/(x-y)(x+y) = y^2 </span>
Приводим к общему знаменателю, получается: 12х/12-х/12=44/12
11х/12=44/12 11х=44 х=4