Question

All the info is in the pictures

Answer 1

bearing in mind that an absolute value expression is in effect a piece-wise function with two cases, thus


`\bf |-n|= \begin{cases} +(-n)\\ -(-n) \end{cases}\implies \begin{cases} -n\\ n \end{cases} \\\\\\ n|-n|=2n\implies \begin{cases} n-n=2n\implies 0=2n\implies &0=n\\ n+n=2n\implies 2n=2n\impliedby &inconsistent \end{cases}`