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 & 0 \\ -2 & 1 \end{bmatrix} & B&= \begin{bmatrix} 2 & 3 \\ 4 & 6 \end{bmatrix} \end{align*}