375,887 views
16 votes
16 votes
4^4x - 1 = 8^2xSolve for x.

User ILuvLogix
by
2.7k points

1 Answer

21 votes
21 votes

x = 1

Step-by-step explanation:


4^(4x-1)=8^(2x)

Make the base have the same number:

8 = 2³

4 = 2²

The base becomes 2


2^(2(4x-1))=2^(3()^(2x))

Then we simplify:


\begin{gathered} \text{The base cancels out:} \\ 2(4x-1)\text{ = 3(2x)} \\ 8x\text{ - 2 = 6x} \\ \text{collect like terms: } \\ 8x\text{ - 6x = 2} \\ 2x\text{ = 2} \\ x\text{ = 2/2} \\ x\text{ = 1} \end{gathered}

Therefore, x = 1

check:


\begin{gathered} 4^(4(1)-1)=8^(2(1)) \\ 4^(4-1)=8^2 \\ 4^3\text{ }=8^2 \\ 4*4*4=\text{ 64} \\ 8*8\text{ = 64} \\ 64\text{ = 64 (x=1 is correct)} \end{gathered}

User Marcel Molina
by
2.7k points
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