SOLUTION: Is there someone that can help me with this problem? I've done these before but have since forgotten. log sqrt(x^3-9)=2 Do I need to add the 9 and leave Log sqrt(x^3) =11?

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Is there someone that can help me with this problem? I've done these before but have since forgotten. log sqrt(x^3-9)=2 Do I need to add the 9 and leave Log sqrt(x^3) =11?      Log On


   



Question 117717: Is there someone that can help me with this problem? I've done these before but have since forgotten.
log sqrt(x^3-9)=2
Do I need to add the 9 and leave Log sqrt(x^3) =11?

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
log%2810%2C%28sqrt%28x%5E3-9%29%29%29=2 Start with the given equation. Note: Since you did not specify a base, this means that we're going to use the default base 10.


10%5E%282%29=sqrt%28x%5E3-9%29 Rewrite the equation using the property: log%28b%2C%28x%29%29=y ====> b%5Ey=x


100=sqrt%28x%5E3-9%29 Evaluate 10%5E%282%29 to get 100


10000=x%5E3-9 Square both sides


10009=x%5E3 Add 9 to both sides


root%283%2C10009%29=x Take the cube root of both sides



So our answer is x=root%283%2C10009%29 which is approximately x=21.5508082663667