Which expressions are equivalent to 2^5•2^4? Check all that apply.

Option A: [tex]2^9[/tex]
Option E: [tex]2^{-2}.2^{11}[/tex]
Option F: [tex](2.2.2.2.2)(2.2.2.2)[/tex]
Solution:
Given expression is [tex]2^5.2^4[/tex].
To find which expression is equivalent to the given expression.
Option A: [tex]2^9[/tex]
Using exponent rule: [tex]a^b.a^c=a^{(b+c)}[/tex]
[tex]2^5.2^4=2^{(5+4)}=2^9[/tex]
Therefore [tex]2^9[/tex] is equivalent to the given expression.
Option B: [tex]2^{20}[/tex]
It is not equivalent to the given expression.
Option C: [tex]2.2^9[/tex]
[tex]2.2^9=2^{(1+9)}=2^{10}[/tex]
Therefore, It is not equivalent to the given expression.
Option D: [tex]2^{10}.2^2[/tex]
[tex]2^{10}.2^2=2^{(10+2)}=2^{12}[/tex]
Therefore, It is not equivalent to the given expression.
Option E: [tex]2^{-2}.2^{11}[/tex]
[tex]2^{-2}.2^{11}=2^{(2-11)}=2^9[/tex]
Therefore, It is equivalent to the given expression.
Option F: [tex](2.2.2.2.2)(2.2.2.2)[/tex]
[tex](2.2.2.2.2)(2.2.2.2)=2^5.2^4[/tex]
Therefore, It is equivalent to the given expression.
Hence option A, Option E and Option E are equivalent to the given expression.