Question 267182
You're going to kick yourself when you see your mistake:
solve for x 
3 = log 8 + 3 log x 
Here's what I tried: 
3 = log 8 + log x^3
3 = log 8x^3
10^3 = 10^(log8x^3)
This is all correct up to this point. And, as your works hows, 10^(log8x^3) = 8x^3. But what is 10^3? It is 1000. So your equation becomes:
1000 = 8x^3
Divide by 8
125 = x^3
Cube root of each side:
5 = x