case 1 suppose we have two terms 7ab and

Question

Case 1: Suppose we have two terms 7ab and 3ab. When we multiply these two terms, we get 7ab x 3ab = (7 x 3) a^{1 + 1} . b^{1 + 1}  ( Therefore, x^m . xⁿ = x^{m + n}) = 21a²b². The product of 7ab x 3ab will be the same as that of 3ab x 7ab. Irrespective of the order of multiplication, the product of two positive terms will be a positive term.

Similarly, the product of 8a²b and 3a²b

                   = (8 x 3) a² . a²  b . b

                   = 24 a²⁺² b¹⁺¹

                   = 24 a⁴ b²

Case 2:  Suppose we have to compute the product of -7ab and -3ab, it will be equal to (-7 x -3) a²b² = 21a²b², i.e. multiplication of two negative quantities gives us a positive quantity.