1. Chapter 3 – Solving Linear Equations Algebra I A - Meeting 18 Section 3.7 Extension – Find Percent of Change Percent of Change – the ratio of the amount of increase or decrease to the original amount. Percent of change, p% = Amount of Increase or Decrease Amount of Increase – the new amount minus the original amount Original Amount Amount of Decrease – the original amount minus the new amount Percent of Increase – The percent of change in a quantity when the new amount of the quantity is greater than the original amount. Percent of Decrease – The percent of change in a quantity when the new amount of the quantity is less than the original amount. If you know the original amount and the percent of change, you can find the new amount by: For a p% increase, multiply the original amount by (100% +p%). For a p% decrease, multiply the original amount by (100% - p%).

2. Chapter 3 – Solving Linear Equations Algebra I A - Meeting 18 Example # 1 A survey asked 220 students to name their favorite pasta dish. Find the percent of students who chose the given pasta dish. Section 3.7 – Solve Percent Problems a) Macaroni and Cheese b) Lasagna Type of PastaStudents Spaghetti83 Lasagna40 Macaroni and Cheese 33 Fettucine Alfredo22 Baked Ziti16 Pasta Primavera15 Other11 Write percent equation.a) Substitute 33 for a and 220 for b. Divide each side by 220. Write decimal as a percent 15 % of the students chose Macaroni and Cheese as their favorite dish. Write percent equation.b) Substitute 40 for a and 220 for b. Divide each side by 220. Write decimal as a percent 18 % of the students chose Lasagna as their favorite dish.

3. Chapter 3 – Solving Linear Equations Algebra I A - Meeting 18 Example # 2 A survey asked 180 students how much they would tip for a $28 meal. Find the percent of students who would tip the given amount. Section 3.7 – Solve Percent Problems a) $4.20 b) $5.60 Amount of TipStudents $2.0016 $2.8028 $3.0045 $4.2036 $5.0047 $5.608 Write percent equation.a) Substitute 36 for a and 180 for b. Divide each side by 180. Write decimal as a percent 20 % of the students would tip $4.20 for a $28 meal. Write percent equation.b) Substitute 8 for a and 180 for b. Divide each side by 180. Write decimal as a percent 4.4 % of the students would tip $5.60 for a $28 meal.

4. Chapter 3 – Solving Linear Equations Algebra I A - Meeting 18 Work in Groups on Worksheet 3.7 - # 17 & # 19 – Show all Work Section 3.7 – Solve Percent Problems Homework # 14 pg 183 # 1 – 14 all Worksheet 3.7 #18 – 20