Question

Поясните решение, пожалуйста.

Answer 1

$Formylu:\\\\\star \; \; \; |a|= \left \{ {{a\; ,\; esli\; a\geq 0} \atop {-a\; ,\; esli \; a\ \textless \ 0}} \right. \; ,\; \; \; |a|=|-a|\; \; ,\; \; \sqrt{a^2}=|a|\; \; \star \\\\t\ \textless \ 0\; \; \; \Rightarrow \; \; \; |t|=-t\; ,\; \; \; \; (-t\ \textgreater \ 0)\\\\|-t|=|t|\\\\ \sqrt{25t^2+1-10t} +5|-t|=\sqrt{(5t-1)^2}+5|t|=|5t-1|+5\cdot (-t)=\\\\=[\; esli\; \; t\ \textless \ 0\; ,\; to\; \; \; 5t-1\ \textless \ 0\; \; \Rightarrow \; \; \; |5t-1|=-(5t-1)=1-5t\; ]=\\\\=1-5t-5t=1-10t$