Multiply two 8 × 8 matrices of your choice, by using the identity in Exercise with these m...

Multiply two 8 × 8 matrices of your choice, by using the identity in Exercise with these matrices and then again for the multiplication of the resulting 4 × 4 matrices.

Exercise

Show that it is possible to multiply two 2 × 2 matrices using only seven multiplications of integers, by using the identity

where x = a11b11 − (a11 − a21 −a22)(b11 − b12 + b22).