Matrices

123456
Across
  1. 3. when m=n
  2. 4. A(B+C)=AB+AC
  3. 5. a rectangular array of numbers
  4. 6. is called in a sub ij
Down
  1. 1. every element of which is zero
  2. 2. if and only if the matrices have the same order
  3. 4. a11,a22,...,ann