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Laws similar to those for addition also apply to multiplication. Special attention should be given to the multiplicative identity and inverse The product of any two real numbers a and b is again a real number, denoted a•b or, more simply, ab. No matter how terms are grouped in carrying out multiplications, the product will always be the same: (ab)c = a (bc). This is called the associative law of multiplication. Given any real number a, there is a number one (1) called the multiplicative identity, such that a(1) = 1(a) = a. Given any real number a, there is a number (a-1), or (1/a), called the multiplicative inverse, such that a(a-1) = (a-1)a = 1. No matter in what order multiplication
is carried out, the product will always be the same: ab = ba.
This is called the commutative law of multiplication. |