Combining Like Terms

True or False? Explain your answer. Warm Up OBJECTIVE: Students will be able to determine if expressions are equivalent by combining like terms. Language Objective: Students will be able to explain in words how to combine like terms. True or False? Explain your answer. a. b. c. d. True True False True

Launch- What is the Area? What is the area of the rectangle? x 4 3 x 4 3 x 7 x 4 3 x 4x 3x 7x + Area = 4x + 3x Area = 7x

We just combined all the x’s! Explore- Using Tiles Think back to the warm up . We just combined all the x’s! Let each x represent a red tile. So, how many tiles would we need? x x x Can we represent 3x another way using tiles? . x x x +

+ x x x Using your tiles, what would you get if you combined 2x + 4x? Explore- Using Tiles Turn and Talk… Using your tiles, what would you get if you combined 2x + 4x? Now combine! + x x x Is this the only way to show 6x?

+ + 3x 3x + 5x + 1 x x x x x Is this the only way to show 6x? Explore- Using Tiles Turn and Talk… Is this the only way to show 6x? + x x + 3x 3x + x x 5x + 1 x

y y y y x x x x What would you get if you combined Explore- Using Tiles Turn and Talk… What would you get if you combined 5x + 3y + 2x + y? Use your tiles. y + y y + y x x x + x + + +

Identify variables that are the same Summary- No Tiles How can we combine without using tiles? Identify variables that are the same 5x 5x + 3y + 2x + y + 3y + 2x y + Commutative Property Now Combine! +

Vocabulary Summary- Vocabulary Example Term: a single number, variable, or number and variables multiplied together. are terms in this expression. Like Terms: terms that have the same variable or power. and and

Process 5x + 3y 2x + y + 1. Copy the expression Summary- Process Process 1. Copy the expression 2. Identify the like terms 5x + 3y 2x + y + 3. Rewrite using the Commutative Property 4. Combine the variables that are the same

With your partner, write an equivalent expression for the following: Summary- Quick Check With your partner, write an equivalent expression for the following: #1. 4a + 6b + 3a + 9b #2. 15x – 4x + 12 #3. y + y + y #4. 5y + 7z 7a + 15b 11x + 12 3y 5y + 7z

Practice- Partners I. Model the following expression by drawing squares. Let = x = y a. b. + +

II. Explain why the following statement is true. Practice- Partners II. Explain why the following statement is true. 2x and 4y are not like terms, therefore, you cannot combine them.

Write an equivalent expression for the following expressions. Practice- Partners Write an equivalent expression for the following expressions. 1. 2. 3.

IV. Explain Yvonne’s mistake in the following problem. Practice- Partners IV. Explain Yvonne’s mistake in the following problem. Yvonne just added all the numbers together. She can add numbers that are the like terms, 8x and 6x, but not 2 since it does not have an x. .

Assessment- Exit Slip Jose and Amy were asked to combine 7x + 2y + 6y + 3x. Decide who is correct. Explain. Jose 7x + 2y + 6y + 3x Amy 7x + 2y + 6y + 3x Jose’s work 7x + 3x + 2y + 6y 10x + 8y 18xy 7x + 2y + 6y + 3x = 18xy Amy’s work 7x + 3x + 2y + 6y 10x + 8y 7x + 2y + 6y + 3x = 10x + 8y