Question

How do you solve `Log_2 x^7=21`?

Answer 1

`x=8`

Explanation:

Using basic properties of logs we find:

`21 = log_2 x^7 = 7 log_2 x`

Dividing both ends by `7` we have:

`3 = log_2 x`

So:

`2^3 = 2^(log_2 x) = x`

That is:

`x = 2^3 = 8`