2Do NowList words that indicate each operation.1. addition2. multiplicationEvaluate each expression.3. 3x for x = 24. 5x – 4 – 3x for x = 7Simplify each expression.5. 3(2x)6. 4(x + y)
3ObjectiveTSW simplify and evaluate algebraic expressions.
4There are three different ways in which a basketball player can score points during a game. There are 1-point free throws, 2-point field goals, and 3-point field goals. An algebraic expression can represent the total points scored during a game.
5Possible Context Clues To translate a real-world situation into an algebraic expression, you must first determine the action being described. Then choose the operation that is indicated by the type of action and the context clues.ActionOperationPossible Context CluesCombineAddHow many total?Combine equal groupsMultiplyHow many altogether?SeparateSubtractHow many more? How many remaining?Separate into equal groupsDivideHow many in each group?
6Example 1: Translating Words into Algebraic Expressions Write an algebraic expression to represent each situation.A. the number of apples in a basket of 12 after n more are addedB. the number of days it will take to walk 100 miles if you walk M miles per day
7Example 1 continuedWrite an algebraic expression to represent each situation.c. Lucy’s age y years after her 18th birthdayd. the number of seconds in h hours
81. Parentheses and grouping symbols. 2. Exponents. To evaluate an algebraic expression, substitute a number for each variable and simplify by using the order of operations. One way to remember the order of operations is by using the mnemonic PEMDAS.Order of Operations1. Parentheses and grouping symbols.2. Exponents.3. Multiply and Divide from left to right.4. Add and Subtract from left to right.
9Example 2: Evaluating Algebraic Expressions Evaluate the expression for the given values of the variables.2x – xy + 4y for x = 5 and y = 2
10Example 3: Evaluating Algebraic Expressions Evaluate the expression for the given values of the variables.q2 + 4qr – r2 for r = 3 and q = 7
11Example 4Evaluate x2y – xy2 + 3y for x = 2 and y = 5.
12Recall that the terms of an algebraic expression are separated by addition or subtraction symbols. Like terms have the same variables raised to the same exponents. Constant terms are like terms that always have the same value.
13To simplify an algebraic expression, combine like terms by adding or subtracting their coefficients. Algebraic expressions are equivalent if they contain exactly the same terms when simplified.Terms that are written without a coefficient have an understood coefficient of 1.x2 = 1x2Remember!
17Example 8: ApplicationApples cost $2 per pound, and grapes cost $3 per pound.Write and simplify an expression for the total cost if you buy 10 lb of apples and grapes combined.
18Example 9: ApplicationApples cost $2 per pound, and grapes cost $3 per pound.What is the total cost if 2 lb of the 10 lb are apples?
19Example 10A travel agent is selling 100 discount packages. He makes $50 for each Hawaii package and $80 for each Cancún package.Write an expression to represent the total the agent will make selling a combination of the two packages.
20Example 11How much will he make if he sells 28 Hawaii packages?
21Example 12Holly’s hybrid car gets 45 miles per gallon on the highway and 25 miles per gallon in the city.Write & simplify an expression for the total number of miles she can drive if her fuel tank hold 15 gallons of gas.Let h = # gallons used on the highway.How many total miles can she drive on one tank of gas if she used 5 gallons on the highway?
23Lesson Quiz: Part IWrite an algebraic expression to represent each situation.1. the number of cards in a 52-card deck after n cards are dealt.2. the number of days in W weeks3. Evaluate: rq2 + 3qr + r2 for r = 5 and q = 2.4. Simplify: 5h2 + 4k + 7h – 4h2.
24Lesson Quiz: Part IIJake has only nickels and dimes in his pocket.5. Write and simplify an expression for the total value if Jake has 20 coins.6. How much does he have if he has 7 nickels?
25Lesson Quiz: Part IWrite an algebraic expression to represent each situation.1. the number of cards in a 52-card deck after n cards are dealt.2. the number of days in W weeks3. Evaluate: rq2 + 3qr + r2 for r = 5 and q = 2.4. Simplify: 5h2 + 4k + 7h – 4h2.52 – n7W75h2 + 4k + 7h
26Lesson Quiz: Part IIJake has only nickels and dimes in his pocket.5. Write and simplify an expression for the total value if Jake has 20 coins.6. How much does he have if he has 7 nickels?Possible answer: $2 – ($0.05)N$1.65