1-6
1-6 Combining
CombiningLike
LikeTerms
Terms
Warm Up
Problem of the Day
Lesson Presentation
Pre-Algebra
Pre-Algebra
1-6 Combining Like Terms
Warm Up
Solve.
1.
2.
3.
4.
9 + 13  5 + 3 20
16  8 + 4  1 11
6 + 9  10 + 3 8
17 + 8  20  2 3
Pre-Algebra
1-6 Combining Like Terms
Problem of the Day
Ray and Katrina are wandering through
the wildlife preserve. They observe and
count a total of 15 wild turkeys and deer
and a total of 46 legs. How many of
each did they see? 7 turkeys, 8 deer
Pre-Algebra
1-6 Combining Like Terms
Learn to combine like terms in an expression.
Pre-Algebra
1-6 Combining Like Terms
Vocabulary
term
like term
equivalent expression
simplify
Pre-Algebra
1-6 Combining Like Terms
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.
Pre-Algebra
1-6 Combining Like Terms
Additional Example 1: Combining Like Terms To
Simplify
Combine like terms.
A. 14a – 5a
9a
Identify like terms.
B. 7y + 8 – 3y – 1 + y
Identify like terms ; the
coefficient of y is 1, because
1y = y.
5y + 7
Pre-Algebra
Combine coefficients: 14 – 5 = 9
Combine coefficients: 7 – 3 + 1 = 5
and 8 – 1 = 7
1-6 Combining Like Terms
Additional Example 2A: Combining Like Terms in
Two-Variables Expressions
Combine like terms.
A. 9x + 3y – 2x + 5
9x + 3y – 2x + 5
Identify like terms.
7x + 3y + 5
Combine coefficients: 9 – 2 = 7
Pre-Algebra
1-6 Combining Like Terms
Additional Example 2B: Combining Like Terms in
Two-Variable Expressions
Combine like terms.
B. 5t + 7p – 3p – 2t
5t + 7p – 3p – 2t
Identify like terms.
4p + 3t
Combine coefficients: 5 – 2 = 3
and 7 – 3= 4
Pre-Algebra
1-6 Combining Like Terms
Additional Example 2C: Combining Like Terms in
Two-Variable Expressions
Combine like terms.
C. 4m + 9n – 2
4m + 9n – 2
Pre-Algebra
No like terms.
1-6 Combining Like Terms
To simplify an expression, perform all
possible operations, including
combining like terms.
Pre-Algebra
1-6 Combining Like Terms
Additional Example 3: Simplifying Algebraic
Expressions by Combining Like Terms
Simplify 6(5 + n) – 2n.
6(5 + n) – 2n
6(5) + 6(n) – 2n
Distributive Property.
30 + 6n – 2n
6n and 2n are like terms.
30 + 4n
Combine coefficients 6 – 2 = 4
Pre-Algebra
1-6 Combining Like Terms
Additional Example 4: Solving Algebraic Expressions
by Combining Like Terms
Solve x + 3x = 48.
x + 3x = 48
4x = 48
Combine coefficients: 1 + 3 = 4
4x = 48
4
4
Divide both sides by 4.
x = 12
Pre-Algebra
Identify like terms. The coefficient of x is 1.
1-6 Combining Like Terms
Lesson Quiz
Combine like terms.
1. 3x + 4 + 2x 5x + 4
2. 13k + 6  8k + 9 + k 6k + 15
Simplify.
3. 4(3x + 6)  7x 5x + 24 4. 6(x + 5) + 3x 9x + 30
Solve.
5. 6y + y = 42 y = 6
6. 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? $3
Pre-Algebra