Given A=[31−21] and B=[4−32−1]
Find sum of all elements in the matrix A+B-2l.
A+B=[31−21]+[4−32−1]=[7−200]
2l=[2002]
A+B−2l=[7−200]−[2002]=[5−20−2] Sum of all elements in A+B-2I = 5 + 0 + (-2) + (-2) = 5 - 4 = 1
Find sum of all elements in the matrix A+B-2I. [4 marks]