SOLUTION: 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) 3 = 8x^3 3/8 = x^3 (use the calculator to find the cube root

Question 267182: 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)
3 = 8x^3
3/8 = x^3
(use the calculator to find the cube root of 3/8)
(but I know the answer is suppose to be 5)
Answer by jsmallt9(3758) (Show Source): You can put this solution on YOUR website!
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
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