Which two expressions are equivalent?
A
B
C Or
D?

[tex]\longrightarrow{\green{D.\:6x\:+\:9x\:and\:3\:(\:2x\:+3x\:) }}[/tex] ✔
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A.
z + z + z = [tex]{z}^{3}[/tex]
➡ 3z ≠ [tex]{z}^{3}[/tex]
➡ L. H. S ≠ R. H. S
Clearly, the two expressions are not equivalent.
B.
13x + 9 - 2x = 15x + 9
➡ 11x + 9 ≠ 15x + 9
➡ L. H. S ≠ R. H. S
The two expressions are not equivalent.
C.
11 x² + 4x + 9 ≠ 15 x² + 9
➡ L. H. S ≠ R. H. S
The two expressions are not equivalent.
[tex]\boxed{D.}[/tex]
6x + 9x = 3 ( 2x + 3x )
➡ 3 ( 2x + 3x ) = 3 ( 2x + 3x )
➡ L. H. S = R. H. S
Since L. H. S is equal to R. H. S., the two expressions are equivalent.
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