Question

What is x if `log_2(x)+Log_2(x-7)=3`?

Answer 1

I found `x=8`

Explanation:

We can use a property of logs to write it as:
`log_2(x(x-7))=3`
we then use the definition of log to get:
`x(x-7)=2^3`
`x^2-7x=8`
`x^2-7x-8=0`
Two solutons (using the Quadratic Formula):
`x_1=8`
`x_2=-1` this will give a negative argument in the log.