Exercise 19 Page 274

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

Equation: 130 % * x=91
Solution: x=70

Practice makes perfect

We know that 130 % of a number is 91. Let x be this unknown number.

We can write this relationship as a percent equation using x. 130 % * x=91 We will solve this equation using the Multiplication and Division Property of Equality. Let's do it!

130 % * x=91

a %=a/100

130/100 * x=91

a/c* b = a* b/c

130x/100= 91

LHS * 100=RHS* 100

130x/100* 100 =91 * 100

a/100* 100 = a

130x = 91* 100

130x = 9100

Next, we will use the Division Property of Equality to simplify the equation even further.

130x=9100

.LHS /130.=.RHS /130.

130x/130=9100/130

Simplify quotient

x=9100/130

Calculate quotient

x=70

We have that 91 is 130 % of 70.

1 Fractions, Decimals and Percents p.273

2 The Percent Proportion p.273

3 The Percent Equation p.274

4 Percents of Increase and Decrease p.274

5 Discounts and Markups p.275

6 Simple Interest p.275

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