content area top Part 1 Let Upper A equals left bracket Start 2 By 2 Matrix 1st Row 1st Column negative 2 2nd Column 4 2nd Row 1st Column 1 2nd Column 4 EndMatrix right bracket , and Upper B equals left bracket Start 2 By 2 Matrix 1st Row 1st Column negative 2 2nd Column 1 2nd Row 1st Column 4 2nd Column 7 EndMatrix right bracket . a. Find AB, if possible. b. Find BA, if possible. c. Are the answers in parts a and b the same? d. In general, for matrices A and B such that AB and BA both exist, does AB always equal BA