Determine the matrix:[br][br][list][*]m1*m2[/*][/list][list][*]m9=m3*m4[/*][*]m10=m5*m6[/*][*]m11=m7*m8[/*][/list]

Matrix [b]m1m2[/b] is [b][color=#980000]not defined[/color][/b] (i.e., does not exist) [color=#0000ff]because the number of rows of matrix m2 is not equal to the number of columns of matrix m1[/color]. Namely, matrix m2 has 1 row, and matrix m1 has 2 columns.