Compute the product $AB$ of the two matrices below using both the definition of the matrix-vector product (Definition MVP) and the definition of matrix multiplication (Definition MM). \begin{align*} A&= \begin{bmatrix} 1 & 3 & 1\\ 0 & 1 & 0\\1 & 1 & 2 \end{bmatrix} & B&= \begin{bmatrix} 2 & -5 & -1 \\ 0 & 1 & 0\\-1 & 2 & 1 \end{bmatrix} \end{align*}