




получилось биквадратное уравнение.
Замена:
(ОДЗ:
0" alt="t> 0" align="absmiddle" class="latex-formula">)



0" alt="t_2=\frac{2(a^2-b^2)+2(a^2+b^2)}{2}=\frac{2a^2-2b^2+2a^2+2b^2}{2}=\frac{4a^2}{2}=2a^2>0" align="absmiddle" class="latex-formula">

Замена:
x^{2} =2a^{2}" alt="x^{2} =t=>x^{2} =2a^{2}" align="absmiddle" class="latex-formula">



Ответ под буквой С) 