Case 1: Suppose we have two terms 7ab and 3ab. When we multiply these two terms, we get 7ab x 3ab = (7 x 3) a1 + 1 . b1 + 1 ( Therefore, xm . xn = xm + 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.