//(a) FALSE
A=matrix([[1,2,2],[1,2/3,1],[1,2,3]])
B=matrix([[1,2,2],[1,4/3,1],[1,2,3]])      //B[1,1]=2A[1,1]
print det(A)
print det(B)        
(b) FALSE
print A[0,0]*A[1,1]*A[2,2]     //product of pivots
(c)TRUE
print det(A+B)
(d)FALSE
print det(A*B)
(e)TRUE
print det(A*B-B*A)