Powers in Expressions

Part of the Expressions & Data section of Coddy's Pre-Algebra journey. Lesson 7 of 51.

$-{5}^{2}$ is -25. But ${\left(-5\right)}^{2}$ is 25.

In $-{5}^{2}$ , only the 5 is squared: 5 times 5 is 25. Then the minus sign makes it -25.

In ${\left(-5\right)}^{2}$ , the whole -5 is squared: -5 times -5 is 25.

So when n is -5, put -5 in brackets. ${n}^{2}$ becomes ${\left(-5\right)}^{2}$ , which is 25.

Challenge

Find the value v of ${n}^{2}-2n$ when n is -3. Put (-3) in both places. Then work it out.

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All lessons in Expressions & Data

1Variables and Expressions

4Combining Like Terms

7Probability

10Final Challenges

2Evaluating Expressions

5Patterns and Sequences

8Tables and Charts

3The Distributive Property

6Data and Averages

9Perimeter and Area