SOLUTION: how do you solve e^x+7=98?

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: how do you solve e^x+7=98?      Log On


   



Question 240900: how do you solve e^x+7=98?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve:
1) e%5Ex%2B7+=+98 or is it
2) e%5E%28x%2B7%29+=+98?
If it's 1) then subtract 7 from both sides.
e%5Ex+=+91 Take the natural log of both sides.
ln%28e%5Ex%29+=+ln%2891%29 Apply the power rule to the left side.
xln%28e%29+=+ln%2891%29 Substitute ln%28e%29+=+1
x+=+ln%2891%29 Evaluate.
x+=+4.51
Check:
e%5E%284.51%29%2B7+=+90.92%2B7=97.92 almost 98.
If it's 2) then take the natural log of both sides.
ln%28e%5E%28x%2B7%29%29+=+ln%2898%29 Apply the power rule to the left side.
%28x%2B7%29ln%28e%29+=+ln%2898%29 Substitute ln%28e%29+=+1
x%2B7+=+ln%2898%29 Evaluate the right side.
x%2B7+=+4.58 Subtract 7 from both sides.
x+=+-2.42