Exercise 3 Page 257

Let x represent the unknown number. Write and solve a percent equation using x.

100

Practice makes perfect

We know that 5 % of a number is 5. Let x be this unknown number.

We can write this relationship as a percent equation using x. 5 % * x=5 We will solve this equation using the Multiplication and Division Property of Equality. Let's do it!

5 % * x=5

a %=a/100

5/100 * x = 5

a/c* b = a* b/c

5x/100= 5

LHS * 100=RHS* 100

5x/100* 100 =5 * 100

a/100* 100 = a

5x = 5* 100

5x=500

.LHS /5.=.RHS /5.

5x/5=500/5

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Calculate quotient

Cancel out common factors

5x/5=500/5

Simplify quotient

x=500/5

Calculate quotient

x=100

We have that 5 is 5 % of 100.

Try It p.254-255

Self-Assessment for Concept & Skills p.255

Self-Assessment for Problem Solving p.256

Review & Refresh p.257

Concept, Skills, & Problem Solving p.257-258

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