1-3: Algebraic Expressions Solve It! Monday Tuesday Walk Dogs 8-9 a.m. Studio 1-5 p.m. Wednesday Thursday Walk Dogs 8-9 a.m. Studio 1-5 p.m. Studio 1-5 p.m. Friday Saturday Walk Dogs 8-9 a.m. Studio 1-5 p.m. Studio noon4 p.m. During summer vacation you work two jobs. You walk three dogs several times a week and you work part time as a receptionist at a hair studio. You earn $8 per hour as a receptionist and $20 per week per dog. Your weekly schedule (shown above) is the same each week. How much will you earn in 10 weeks? Explain. Example 1: Which algebraic expression models the word phrase seven fewer than a number t? a.) t + 7 b.) -7t c.) t – 7 d.) 7 – t You Try: Which algebraic expression models the word phrase two times the sum of a and b? a.) a + b b.) 2(a + b) Algebra 2: 1-3 Algebraic Expressions c.) 2a + b d.) a + 2b Page 1 Example 2: a.) You start with $20 and save $6 each week. What algebraic expression models the total amount you save? b.) You had $150 but are spending $2 each day. Write an algebraic expression that models this situation. Example 3: What is the value for each expression for the given values of the variables? a.) 7(a + 4) + 3b – 8 for a = -4 and b = 5 b.) 𝑥 4 + 𝑦 2 for x = 1 and y = ½ c.) What is the value of 4(𝑚 − 2) + 3𝑛 + 5 for m = 6 and n = -3? d.) What is the value of 2(𝑥 2 +𝑦 2 ) 3 Algebra 2: 1-3 Algebraic Expressions for x = 6 and y = -3? Page 2 Example 4: Write and evaluate an expression for each. a.) In football, a touchdown (TD) is worth 6 points, an extra-point kick (EPK) is worth 1 point, and a field goal (FG) 3 points. What algebraic expression models the total number of points that a football team scores in a game, assuming each scoring play is one of the three given types? Suppose a football team scores 3 touchdowns, 2 extra-point kicks, and 4 field goals. How many points did the team score? b.) In basketball, teams can score by making two-point shots, three-point shots, and one-point free throws. What algebraic expression models the total number of points that a basketball team scores in one game? If a team makes ten two-point shots, 5 three-point shots, and 7 free throws, how many points does it score in all? Example 5: Combine like terms. What is the simplified form of each expression? a.) 7𝑥 2 + 3𝑦 2 + 2𝑦 2 − 4𝑥 2 b.) −(3𝑘 + 𝑚) + 2(𝑘 − 4𝑚) c.) −4𝑗 2 − 7𝑘 + 5𝑗 + 𝑗 2 d.) −(8𝑎 + 3𝑏) + 10(2𝑎 − 5𝑏) Algebra 2: 1-3 Algebraic Expressions Page 3 Challenge! a.) Combine like terms: −5(2𝑥 3 − 5𝑥 2 + 3𝑥𝑦 + 9𝑥 − 4𝑥𝑦 + 7𝑥 3 − 6𝑥 2 − 𝑥) b.) Evaluate the expression (𝑐 2 −𝑑)3 +2𝑎+𝑏2 5(𝑎+𝑑) for a = 4, b = -2, c = 1, and d = -1 c.) Write an expression that models the following situation: You ask for your bill at a restaurant. You have a $5 off coupon that will be applied after the 6% sales tax. Write an expression for the total amount of money you will pay. Homework: pp. 22 – 23 => 10 – 20; 23 – 31 odd Algebra 2: 1-3 Algebraic Expressions Page 4