1.2 Learn Basic Properties and Operations

This lesson will help you learn the basic properties and rules that govern math problem-solving.

Properties

In a multiplication problem, the numbers being multiplied are called factors. In the expression 4(9 + 2), the factors are 4 and (9 + 2). We can work backward using the distributive property to find the factors in an expression.

Example

Which of the following expressions is equal to $$5(15) - 5(8)$$?

Test Tip

Equal expressions have the same value when all of the operations are completed.

A. $$(15 - 5) - (8 - 5)$$
B. $$(15 - 5) + (8 - 5)$$
C. $$5(15 - 8)$$
D. $$5(15 + 8)$$


Answer

The correct answer is C. In the original expression, there are two terms: 5(15) and 5(8). Both terms have 5 as a factor, so we can factor out the 5, removing it from the terms. Then we write the numbers that are left as a subtraction inside parentheses.

5 times 15 minus 5 times 8 becomes 5 times 15 minus 8

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