Find the product of the elementary matrix EEE corresponding to R2→R2−2R1R_2 \to R_2 - 2R_1R2→R2−2R1 for a 2×22 \times 22×2 matrix.
(10−21)\begin{pmatrix} 1 & 0 \\ -2 & 1 \end{pmatrix}(1−201)
(1−201)\begin{pmatrix} 1 & -2 \\ 0 & 1 \end{pmatrix}(10−21)
(−2011)\begin{pmatrix} -2 & 0 \\ 1 & 1 \end{pmatrix}(−2101)
(11−21)\begin{pmatrix} 1 & 1 \\ -2 & 1 \end{pmatrix}(1−211)