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 3 Page 176

Use the Multiplication Property of Equality to eliminate the coefficient of 29g.

g=- 36

To solve the equation, we have to isolate g on one side. Using the Multiplication Property of Equality, we will multiply both sides of the equation by 92, the reciprocal of 29. This will eliminate the coefficient of 29g and isolate g.
2/9g=- 8
2/9g* 9/2=- 8* 9/2
â–Ľ
Simplify left-hand side
2/9* 9/2g=- 8* 9/2
1g=- 8* 9/2
g=- 8* 9/2
g=- 8* 9/2
g=- 72/2
g=- 36
To check that this solution is correct, let's substitute g=- 36 into the original equation and simplify.
2/9g=- 8
2/9( - 36)? =- 8
- 2/9(36)? =- 8
- 2(36)/9? =- 8
- 72/9? =- 8
- 8=- 8 âś“
Since the left-hand side and right-hand side are equal, g=- 36 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.