Lesson 1 Algebraic Expressions Unit 3A Expressions Lesson 1 Algebraic Expressions

Lesson 1: Algebraic Expressions Objective: Swbat write and evaluate algebraic expressions. Do Now: Worksheet

Lesson 1: Algebraic Expressions Definitions A variable is a symbol that represents an unknown quantity. Algebraic Expression is an expression that contains variables, numbers and at least one operation. Coefficient is the numerical factor multiplied to the variable.

Lesson 1: Algebraic Expressions Real-World Example (F – 32) x 5 9 is an expression that can be used to convert a temperature from Fahrenheit to Celsius. In this algebraic expression, the variable F represents the temperature in degrees Fahrenheit. What would be the temperature in Celsius for 77°F ?

Lesson 1: Algebraic Expressions An algebraic expression such as 6x Coefficient multiplied to Variable is the numerical factor unknown factor

Lesson 1: Algebraic Expressions Evaluate Expressions. 2(n+3) if n = -4 8w – 2v if w=5 and v=3 4 𝑦 3 + 2 if y = 3

Lesson 1: Algebraic Expressions Evaluate each expression if c=8 and d=-5 a.) c – 3 b.) 15 – c c.) 2c – 4d d.) d - 𝑐 2

Lesson 1: Algebraic Expressions Real-World Problem Athletic trainers use the formula 3(220 - a) , 5 where a is a person’s age to find their minimum training heart rate. Find Lisa’s heart rate if she’s 15 years old.

Lesson 1: Algebraic Expressions Write Expressions To translate a verbal phrase into an algebraic expression, the first step is to define a variable. When you define a variable, you choose a variable to represent an unknown quantity.

Lesson 1: Algebraic Expressions Example 1: Marissa wants to buy a DVD player that costs $150. She already saved $25 and plans to save an additional $10 each week. Write an expression that represents the total amount of money Marissa has saved after any number of weeks. Will Marissa have enough money to buy the DVD player in 11 weeks? Words: savings of $25 plus $10 each week Variable: Let w represent the number of weeks Expression: 25 + 10w

Lesson 1: Algebraic Expressions Example 2: An MP3 player costs $70 and song downloads cost $.85 each. Write an expression that represents the cost of the MP3 player and a number of downloaded songs. What is the total cost if 20 songs are downloaded? Words: player costs $70 plus downloads cost $0.85 each Variable: Let x represent number of downloaded songs Expression: 70 + .85x

Classwork Guided Practice #1 – 5 Independent Practice #1 – 12 Problem Solving Practice #1 - 8

Closure Question: What do you need to do to find an unknown quantity? Exit Ticket Homework: Practice

Exit Ticket Evaluate the expression if f = 4 and g = -1 8g – f Write the algebraic expression. The phone company charges a $50 fee and $.02 for each text message.

Homework