Pull up the elements in the second column of the second matrix and invert them to the left. Each element is multiplied by each element in the 1 row of the first matrix, and then summed to obtain a12 = 0x1+1x0+0x0 = 0 of the product matrix.
Similarly, a 13 and a 14 are obtained. ......
Pull the elements in the 1 column of the second matrix up and down to the left. Each element is multiplied by each element in the second row of the first matrix, and then summed to get a 21=1x0+0x1+1x0 = 0 of the product matrix.
Pull up the elements in the second column of the second matrix and invert them to the left. Each element is multiplied by each element in the second row of the first matrix, and then summed to get A22 =1x1+0x0+1x0 =1of the product matrix.
In the same way, a23 and a24 were obtained. ......
A3 1, a32, a33, a34 and so on of product matrix.
The product matrix of A4 1, a42, a43, a44 and so on.