Pearson Algebra 1 Common Core, 2011
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Pearson Algebra 1 Common Core, 2011 View details
6. Multiplying and Dividing Real Numbers
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Exercise 12 Page 42

When multiplying real numbers, the product will be positive if the signs are the same and it will be negative if the signs are different.

-7.7

Practice makes perfect

When multiplying real numbers, the product will be positive if the signs are the same and it will be negative if the signs are different. cc Same Sign & Different Signs (+)(+)=(+) & (+)(-)=(-) (-)(-)=(+) & (-)(+)=(-) In our case, one number is negative and one is positive, so the product will be negative.

- 7 * 1.1
- 7.7

Alternative Solution

Using the Distributive Property
We can also solve this problem using our mental math skills. We are going to use the Distributive Property. Notice that we can rewrite 1.1 as a sum of an integer and a decimal. 1.1 = 1+0.1 ⇔ - 7 * 1.1 = - 7( 1+0.1) We can now calculate the product using the Distributive Property.

- 7(1+0.1)
- 7*1+(- 7)* 0.1
- 7 + (- 0.7)
-7.7

We got the same final solution, - 7.7.