Product Property of
Radicals
For any numbers a and b where a
0 and b
0 ,
ab
a
b
Product Property of
Radicals Examples
72 36
2
36
6 2
2
48
16
3
16
4 3
3
Examples:
1. 30 a
34 a
34
a
17
30
30
2. 54 x
4 y
5 z
7
9 x
4 y
4 z
6
3 x
2 y
2 z
3
6 yz
6 yz
Examples:
3
3. 54 a
3 b
7 3
27 a
3 b
7 3
2 b
3 ab
2 3
2 b
4. 60 xy
3
4 y
2
15 xy
2 y 15 xy
Quotient Property of
Radicals
For any numbers a and b where a
0 and b
0 , a b
a b
Examples:
1.
7
16
7
16 4
7
2.
32
25
32
25
32
5
4 2
5
Examples:
3.
48
3
48
16
4
3
4.
45
4
45
4
45
2
3 5
2
Rationalizing the denominator
Rationalizing the denominator means to remove any radicals from the denominator.
Ex: Simplify
5
3
5
3
3
3
5 3
9
5 3
3
15
3
Simplest Radical Form
•No perfect nth power factors other than 1.
•No fractions in the radicand.
•No radicals in the denominator.
Examples:
1.
5
4
5
4 2
5
2.
20 8
2 2
10
8
2
10 4
10
2
20
Examples:
3.
5
2 2
2
2
5 2
2 4
5 2
2
2
5 2
4
4. 4
5
7x
4 5
7 x
7 x
7 x
4 35
49 x 2 x
4 35 x
7 x
Adding radicals
We can only combine terms with radicals if we have like radicals
6 7
5 7
3 7
6
5
3
7
8 7
Reverse of the Distributive Property
Examples:
1. 2 3 + 5 + 7 3 - 2
= 2 3 + 7 3 + 5 - 2
= 9 3 + 3
Examples:
2. 5 6
3 24
150
= 5 6
3 4 6
25 6
= 5 6
6 6
5 6
= 4 6
Multiplying radicals -
Distributive Property
3
2
4 3
3
2
3
4 3
6
12
Multiplying radicals - FOIL
3
5
F
2
O
4 3
3
2
3
4 3
I
L
5
2
5
4 3
6
12
10
4 15
1. 2 3
Examples:
4 5
3
6 5
F O
2 3
3
2 3
6 5
I
L
4 5
3
4 5
6 5
6
12 15
4 15
120
16 15
126
Examples:
F
2
2 7
5 4
2 7
5
O
10
10
10
2 7
2
2 7
2 7
I L
2 7
10
2 7
2 7
100
20 7
20 7
4 49
100
4
7
72
Conjugates
Binomials of the form
a b
c d and a b
c d where a, b, c, d are rational numbers.
Ex : 5
6
Conjugate: 5
6
3
2 2
Conjugate: 3
2 2
What is conjugate of 2 7
3?
Answer : 2 7
3
The product of conjugates is a rational number. Therefore, we can rationalize denominator of a fraction by multiplying by its conjugate.
Examples:
1.
3
2
3
5
3
5
3
5
3
3
5
3
2 3
2
5
2
5 2
3
7 3
10
3
25
13
7 3
22
Examples:
2.
1
2 5
6
5
6
5
6
5
6
5
12 5
10
6 2
2
16
13 5
31