Big Ideas Math: Modeling Real Life, Grade 7
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Big Ideas Math: Modeling Real Life, Grade 7 View details
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Exercise 5 Page 173

Use the Subtraction Property of Equality to eliminate the addition.

n=- 2/4

Practice makes perfect
To solve the equation, we have to isolate n on one side. Using the Subtraction Property of Equality, we will subtract 34 from both sides of the equation. This will eliminate the addition. Let's do it!
n+3/4=1/4
n+3/4-3/4=1/4-3/4
n=1/4-3/4
n=1-3/4
n=- 2/4
n=- 2/4
To check that this solution is correct, let's substitute n=- 24 into the original equation and simplify.
n+3/4=1/4
- 2/4+3/4? = 1/4
- 2/4+3/4? = 1/4
- 2+3/4? = 1/4
1/4= 1/4 âś“
Since the left-hand side and right-hand side are equal, n=- 24 is the correct solution.

Extra

Properties of Equality

There are four main Properties of Equality that we use when solving linear equations.

Properties of Equality
Addition Property of Equality If a=b, then a+c=b+c.
Subtraction Property of Equality If a=b, then a-c=b-c.
Multiplication Property of Equality If a=b, then ac=bc.
Division Property of Equality If a=b and c is not 0, then a/c=b/c.

In later chapters, you will learn about some more advanced Properties of Equality. As an example, there is a property for when we need to eliminate a radical or an exponent.

Power Property of Equality

If a=b, then a^m=b^m.