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Nyla
10-30-2013, 06:15 AM
Which of the following is the value of a given that 4^4 \cdot 2^8=4^{2a} ?

(A) 2

(B) 4

(C) 8

(D) 16

(E) 32

Thanks!;)

Lucas
10-30-2013, 06:19 AM
Using laws of exponents the initial equation can be rewritten as

4^4 \cdot (2^2)^4=4^{2a} \Rightarrow 4^4 \cdot 4^4=4^{2a} \Rightarrow

4^{4+4}=4^{2a} \Rightarrow 4^8=4^{2a} \Rightarrow 8=2a \Rightarrow a=4


Therefore the correct answer is (B).

Nyla
10-30-2013, 06:19 AM
Thanks Lucas!