Find the rank of the following matrices by row reduction method: 12-13-121-231-11

Find the rank of the following matrices by row reduction method: $[\begin{matrix} 1 & 2 & - 1 \\ 3 & - 1 & 2 \\ 1 & - 2 & 3 \\ 1 & - 1 & 1 \end{matrix}]$

Mixed-up sentence exercise

Put the parts in order to form a sentence. When you think your answer is correct, click on "Check" to check your answer. If you get stuck, click on "Hint" to find out the next correct part.