Question

(x-1)^4-8(x-1)^2-9=0 ответы должны быть -2;4

Answer 1

$\displaystyle (x-1)^4-8(x-1)^2-9=0\\\\(x-1)^2=t; t\ \textgreater \ 0\\\\t^2-8t-9=0\\\\D=64+36=100\\\\t_{1.2}= \frac{8\pm 10}{2}\\\\t_1=9;t_2=-1\\\\(x-1)^2=9\\\\x-1=\pm 3\\\\x-1=3; x=4\\\\x-1= -3; x=-2$