Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
To multiply two integers with the same sign, multiply their absolute values and place a positive sign () before the product. Example: and .
To multiply two integers with unlike signs, multiply their absolute values and place a negative sign () before the product. Example: and .
The product of an even number of negative integers is positive. For example, .
The product of an odd number of negative integers is negative. For example, .
Commutative Property: Multiplication is commutative for integers, meaning for any integers and .
Associative Property: For any three integers and , the grouping of factors does not change the product: .
Distributive Property: Multiplication distributes over addition and subtraction: and .
Multiplicative Identity: The integer is the identity for multiplication. For any integer , .
Multiplication by Zero: Any integer multiplied by zero results in zero: .
📐Formulae
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💡Examples
Problem 1:
Find the product of .
Solution:
Explanation:
First, multiply the absolute values: . Since there are three negative signs (which is an odd number), the final product is negative: .
Problem 2:
Evaluate using the distributive property: .
Solution:
Explanation:
Using the formula , we take , , and . This simplifies the calculation to , resulting in a positive because the product of two negatives is positive.
Problem 3:
Determine the product of and .
Solution:
$$\begin{array}{r} 15 \\ \times (-8) \\ \hline -120 \end{array}$$
Explanation:
Multiply the positive integer by the negative integer . Since the signs are different, the product is negative: , so the result is .
Problem 4:
Find the value of .
Solution:
Explanation:
There are four negative integers. Since is an even number, the product will be positive. Calculating the absolute product: .