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2-9 Percents. Objective to solve problems with proportions and percent equations. 2-9 Percents. You can solve proportionally or with a percent equation. 2-9 Percents. Proportion : = Example: What percent of 50 is 25? = Or Translate words to an equation :
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2-9 Percents Objective to solve problems with proportions and percent equations
2-9 Percents • You can solve proportionally or with a percent equation.
2-9 Percents • Proportion: = • Example: What percent of 50 is 25? • = • Or Translate words to an equation: • What percent of 50 is 25 • p 50 = 25 solve for p
2-9 Percents • Example 1: What percent of 56 is 42? • = or p 56 = 42
2-9 Percents • Example 2: What percent of 40 is 2.5? • = or p 40 = 2.5
2-9 Percents • Example 3: A shirt costs $38.50. It is on sale for 30% off. What is the sale price? • price percent off = discount. • Original price – discount is sale price.
2-9 Percents • Example 4: • 125% of what number is 17.5?
2-9 Percents • Simple Interest is I = Prt • Where I: Interest, P: Principal, • r: rate t: time
2-9 Percents • Simple Interest is I = Prt • Example 5: P. 140 • You deposit $840 in a savings account that earns interest rate of 4.5% per year. You keep the money in the account for 4 years. How much interest will you earn?
2-9 Percents • Homework: p. 141 9 - 43 odds