[tex]\begin{gathered} -1\le2n+4-5 \\ add_{\text{ }}like_{\text{ }}terms\colon \\ -1\le2n-1 \\ add_{\text{ }}1_{\text{ }}to_{\text{ }}both_{\text{ }}sides\colon_{} \\ -1+1\le2n-1+1 \\ 0\le2n \\ 2n\ge0 \\ divide_{\text{ }}both_{\text{ }}sides_{\text{ }}by_{\text{ }}2\colon \\ n\ge\frac{0}{2} \\ n\ge0 \end{gathered}[/tex]
