Combining Like Terms

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1-6
Combining Like Terms
Lesson Presentation
Pre-Algebra
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Learn to combine like terms in an expression.
Vocabulary
term like term equivalent expression simplify
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Terms in an expression are separated by plus or
minus signs.
Like terms can be grouped together because they
have the same variable raised to the same power.
Equivalent expressions have the same value for
all values of the variables.
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Combine like terms.
7y 8 3y 1 y
14a 5a
9a
5y 7
9x 3y 2x 5
5c 8 4c 2 c
7x 3y 5
6
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Combine like terms.
4m 9n 2
2x 5x 4y 3
4m 9n 2
7x 4y 3
To simplify an expression, perform all possible
operations, including combining like terms.
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Simplify 6(5 n) 2n
6(5 n) 2n
6(5) 6(n) 2n
30 6n 2n
30 4n
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Simplify 3(c 7) c.
3(c 7) c
3(c) 3(7) c
3c 21 c
2c 21
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Solve x 3x 48.
x 3x 48
4x 48
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x 12
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Solve 7c c 102.
7c c 102
6c 102
6c 102
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c 17
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• Combine like terms. Simplify.
• 3x 4 2x 2. 4(3x 6) ? 7
• Solve.
• 3. 6y y 42
• 4. The accounting department ordered 15 boxes of
  pens. The marketing department ordered 9 boxes of
  pens. If the total cost of the combined order was
  72, what is the price of each box of pens?

5x 4
12x 17
y 6
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Homework

• Pg 30
• 1 47 odd