What is the result of R1←R1+2R2R_1 \leftarrow R_1 + 2R_2R1←R1+2R2 applied to (10−21)\begin{pmatrix} 1 & 0 \\ -2 & 1 \end{pmatrix}(1−201)?
(−32−21)\begin{pmatrix} -3 & 2 \\ -2 & 1 \end{pmatrix}(−3−221)
(−31−21)\begin{pmatrix} -3 & 1 \\ -2 & 1 \end{pmatrix}(−3−211)
(−3201)\begin{pmatrix} -3 & 2 \\ 0 & 1 \end{pmatrix}(−3021)
(1001)\begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}(1001)