You have enough wallpaper to cover 140 square feet. If your walls are 7 high, wall length can you paper? Solve the problem by applying the four steps of problem solving

Matrix A has 3 rows, 2 columns
Matrix B has 3 rows, 2 columns

The number of columns in matrix A (which is 2) does not match up with the number of rows in matrix B (which is 3). 

So the matrix multiplication A*B is undefined. We cannot multiply the matrices.