Download Lesson 5-5

Lesson 5-5
Example 1 Add Fractions
4 7
Find + . Write the sum in simplest form. Estimate: 0 + 1 = 1
9
9
4
7
4+7
+ =
The denominators are the same. Add the numerators.
9
9
9
11
Simplify.
=
9
2
11
=1
Rename
as a mixed number.
9
9
Example 2 Add Mixed Numbers
4
8
+ 6 . Write the sum in simplest form.
Estimate: 3 + 7 = 10
Find 3
15
15
4
8
 4 8
3
+6
= (3 + 6) +  +  Add the whole numbers and the fractions separately.
15
15
 15 15 
4+8
Add the numerators.
=9+
15
12
4
=9
or 9
Simplify.
15
5
Example 3 Subtract Fractions
7
11
3
1
Find
. Write the difference in simplest form. Estimate:
-1=4
4
12 12
7 11 7 − 11
=
The denominators are the same. Subtract the numerators.
12 12
12
−4
1
or Simplify.
=
12
3
Example 4
Subtract Mixed Numbers
7
2
Evaluate x – y if x = 7 and y = 4 .
Estimate: 8 - 4 = 4
8
8
7
2
7
2
x–y=7 -4
Replace x with 7 and y with 4 .
8
8
8
8
63 34
=
Write the mixed numbers as improper fractions.
8
8
29
Subtract the numerators.
=
8
5
=3
Simplify.
8
Example 5 Add Algebraic Fractions
3p
p
+ . Write the sum in simplest form.
Find
11 11
p
3p
3p + p
+
=
The denominators are the same. Add the numerators.
11
11
11
4p
=
Simplify.
11