Combining Like Terms & Solving Equations

​Bell Ringer

​Combine like terms to simplify the expressions.

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​1. 8x - 6y + x - 2y

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​2. 7x² - 1/4 x - 4x²

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​THEN, Join this Quizizz.

Open Ended

How do you know that two numbers are "Like Terms" and can be combined?

Multiple Choice

3y = -15

• -5
• 5
• -3
• 3

Multiple Choice

-4x + 1 = 21

• x=120
• x=5
• x=30
• x=-5

Multiple Choice

12x = 144

• x = 12
• x = 4
• x = 2
• x = 132

Multiple Choice

What should you do first when solving for x?

2x - 8 = 16

• Divide by 2

• Subtract 8 from both sides

• Subtract 16 from both sides

• Add 8 to both sides

​Sometimes, when you are solving equations, you will need to combine like terms before you can solve it. In other words, it is easier to get your variable on its own if all of that variable is combined into one term on one side of the equal sign.

Poll

Which of these would be easier/faster to solve?

• 5x + 2x = 21

• 1x + 6x = 21

• 2x + 3x + 2x = 21

• 7x = 21

​The first thing you will want to do with an equation is scan it and make sure that all your variables are on one side. Then, you will want to combine any like terms that you can. Finally, you should solve the equation like normal.

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​Let's try some examples!

Multiple Choice

Which of the following is a valid first step in solving the following?

2x - 3 + 4x = 27

• 6x - 3 = 27

• -2x + 3 = 27

• -2x - 3 = 27

• 6x + 3 = 27

Multiple Choice

$$5+30=x+10$$  

• 25

• -45

• -25

• 45

Multiple Choice

Combine like terms and solve the 2-step equation:

3 + 12c - 4c = 35

• c = 4

• c = 2

• c = 4.75

• c = 3.18

Multiple Choice

Combine like terms and solve the 2-step equation:

3x + 20 - 5 = 36

• x = 17

• x = 3.6

• x = 20.3

• x = 7

​Homework! (Copy these down on a sheet of paper!)