SOLUTION: Solve- 7e^3x + 5 = 40 * round to the nearest thousandth * must be an algebraic solution

Algebra ->  Equations -> SOLUTION: Solve- 7e^3x + 5 = 40 * round to the nearest thousandth * must be an algebraic solution      Log On


   

Question 1022326: Solve- 7e^3x + 5 = 40
* round to the nearest thousandth
* must be an algebraic solution
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+7%2Ae%5E%283x%29+%2B+5+=+40+
+7%2Ae%5E%283x%29+=+35+
+e%5E%283x%29+=+5+
Take the natural log of both sides
+3x+=+ln%285%29+
+x+=+%281%2F3%29%2Aln%285%29+
+x+=+1.60944%2F3+
+x+=++.536+
----------------
check:
+7%2Ae%5E%283x%29+%2B+5+=+40+
+7%2Ae%5E%283%2A.536%29+%2B+5+=+40+
+7%2Ae%5E1.608+%2B+5+=+40+
+7%2A4.993+%2B+5+=+40+
+34.95+%2B+5+=+40+
+39.95+=+40+
error due to rounding off