Question

How do you solve `log x + log (x-3)=1`?

Answer 1

`b = 10 Rightarrow x = (3 + 7)/2 = 5`

Explanation:

`log_b [x(x-3)] = log_b b`

`x(x-3) = b`

`x^2 -3x - b = 0`

`x = (3 ± sqrt{9 + 4b})/2`

Consider `x > 0` and `x - 3 > 0`