Practice problem
Given the matrix [182010001]\begin{bmatrix}1&8&2\\0&1&0\\0&0&1\end{bmatrix}100810201 select the row operations that give you the identity matrix.
−18 R1+R2⟶R2-\frac18\ R_1+R_2\longrightarrow R_2−81 R1+R2⟶R2
−18 R2+R1⟶R1-\frac18\ R_2+R_1\longrightarrow R_1−81 R2+R1⟶R1
−8R2+R1⟶R1-8R_2+R_1\longrightarrow R_1−8R2+R1⟶R1
−2R3+R1⟶R1-2R_3+R_1\longrightarrow R_1−2R3+R1⟶R1
−2R3+R2⟶R2-2R_3+R_2\longrightarrow R_2−2R3+R2⟶R2
Type a concept, like “slope” or “photosynthesis”.
