Answer:
x=2.4650
Step-by-step explanation:
I assume that you mean 
so let s use the ln() function

so x = ln(15)/ln(3)
x = 2.4650
The answer to the question is 2,085,000
8 times 3 equals 23 and that is one of the answers
She would have $800 left.
$4000 - $2800= 1200
1200 is how much she spent the last 3 months
1200/ 3= 400
400 * 5= $2000
2800- 2000= $800