Name____________________________
Class/Period_________________
Date__________________________
HW: Adding and Subtracting Rational Expressions
Find the least common multiple for each pair.
1. 3x2y6 and 5x3y2
2. x2  x  2 and x2  x  6
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Add or subtract. Identify any x-values for which the expression is undefined.
3.
2x  3 4 x  5

x4
x4
4.
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5.
x4
2x

2
x  x  12 x  4
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6.
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7.
x2
x

x  2x  15 x  3
2
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x  12 3 x  2

2x  5 2x  5
3x 2  1
x2

2
x  3 x  18 x  6
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8.
x6
2x

x  7 x  18 x  9
2
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Name____________________________
Answers
1. 15x3y6
2. (x  1)(x  2)(x  3)
3.
6x  8
; x  4
x4
4.
2x  14
5
;x 
2x  5
2
5.
2x 2  7 x  4
; x  4, x  3
x 2  x  12
6.
2x 2  5 x  7
; x  6, x  3
x 2  3 x  18
7.
x 2  4x  2
; x  3, x  5
x 2  2x  15
8.
2x 2  3 x  6
; x  2, x  9
x 2  7 x  18
9.
x 2  4x  3
x 2  11x  30
10.
12x  24
x  3x 2  x  3
3
Class/Period_________________
Date__________________________