Add and subtract with the same denominator

1
Example 1
Add and subtract with the same denominator
Find the sum or difference.
Add numerators.
Simplify.
2
Example 1
Add and subtract with the same denominator
Find the sum or difference.
Add numerators.
Simplify.
Factor and divide out common factor.
Simplify.
3
Checkpoint. Find the sum or difference.
4
Example 2
Find the LCD of rational expressions
Find the LCD of the rational expressions.

• Find the ______________________ of 3x3 and 4x4.

least common multiple
Write prime factorization.
Circle common factors.
Factors inside circle.
Factors outside circle.
The LCD of and is ______.
5
Example 2
Find the LCD of rational expressions
Find the LCD of the rational expressions.

• Find the ______________________ of x2 4 and x2
  x 2

least common multiple
The LCD of and
is __________________________.
6
Checkpoint. Find the LCD of the rational
expression.
7
Checkpoint. Find the LCD of the rational
expression.
8
Example 3
Add expressions with different denominators
Find the sum .
Rewrite fractions using LCD, ______.
Simplify numerators and denominators.
Add fractions.
9
Example 3
Subtract expressions with different denominators
Find the difference
.
10
Checkpoint. Find the sum or difference.
11
Checkpoint. Find the sum or difference.
12
Checkpoint. Find the sum or difference.
13
Checkpoint. Find the sum or difference.
14
Pg. 189, 3.10 1-21