SOLUTION: How do I solve the equation 5X=72. If needed I can round to the nearest three decimal places. NOTE: the (x) following the 5 should be written as expanded notation. I just do n

Algebra ->  Equations -> SOLUTION: How do I solve the equation 5X=72. If needed I can round to the nearest three decimal places. NOTE: the (x) following the 5 should be written as expanded notation. I just do n      Log On


   

Question 113513: How do I solve the equation 5X=72. If needed I can round to the nearest three decimal places.
NOTE: the (x) following the 5 should be written as expanded notation. I just do not know how to write it like that on the computer.
Found 2 solutions by checkley71, Earlsdon:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
5^X=72
USING THE TRIAL & ERROR METHOD I GET:
5^2.657242=72
71.99999268~72

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
I'm not certain what you mean by "expanded notation" but I suspect that it means "raised to the power of", so, with that in mind, let's proceed...
5%5Ex+=+72 Take the logarithm of both sides.
Log%285%5Ex%29+=+Log%2872%29 Apply the power rule for logarithms to the left side:Log%5Bb%5D%28M%5Ep%29+=+p%2ALog%5Bb%5D%28M%29.
x%2ALog%285%29+=+log%28%2872%29%29 Divide both sides by log(5).
x+=+log%28%2872%29%29%2FLog%285%29
x+=+2.657
Check:
5%5Ex+=+72 Substitute x = 2.657
5%5E2.657+=+71.995