Introduction to Real Numbers and Algebraic Expressions 1.5

1.5 MULTIPLICATION of REAL NUMBERS
a. Multiply real numbers.
b. Solve applied problems involving multiplication of real numbers.

Objective a
Multiply real numbers.

Multiplication of real numbers is like multiplication of arithmetic numbers. The difference is that we must determine whether the answer is positive or negative.The

Product of a Positive and a Negative Number
To multiply a positive number and a negative number, multiply their absolute values. The answer is negative.

Example A



The Product of Two Negative Numbers
To multiply two negative numbers, multiply their absolute values. The answer is positive.

Example B



To multiply two nonzero real numbers:
a) Multiply the absolute values.
b) If the signs are the same, the answer is positive.
c) If the signs are different, the answer is negative.



Example C



The product of an even number of negative numbers is positive.

The product of an odd number of negative numbers is negative.

Example D



Example E



Objective b
Solve applied problems involving multiplication of real numbers.

Example F