MATD 0390 Intermediate Algebra
Christy Dittmar
Section 6.4 notes: Adding, Subtracting, and Multiplying Radical Expressions
Adding, Subtracting, and Multiplying Radical Expressions (6.4)
Like Radicals
Like radicals have the same index and the same radicand.
Like radicals
Not like radicals
2 3, 5 3
2 3 , 53 3
!
5
7
, 10 5 7
2
! 5 7 , 10 5 2
To add or subtract, combine like radical terms. 2 3+5 3
5
2 ! 73 2 ! 25 2 ! 3 2
You may need to simplify each term before you are able to combine them. 20 ! 45
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MATD 0390 Intermediate Algebra
Christy Dittmar
Section 6.4 notes: Adding, Subtracting, and Multiplying Radical Expressions
3
54x 2 + 3 128x 2
Multiply and simplify. 2
(
5 ! 3 2x
(
10 ! 5 3
(
2x + 7
)
)(
)
2+2 3
)
2
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MATD 0390 Intermediate Algebra
Christy Dittmar
Section 6.4 notes: Adding, Subtracting, and Multiplying Radical Expressions
Multiplying conjugates Multiply and simplify. ( 5 + 2 )( 5 ! 2 )
Radical functions
f ( x ) = 8x and g ( x ) = 2x . Find the following.
( f + g )( x )
( f + g ) (16 )
( f ! g )( x )
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