SOLUTION: use natural log to solve: 9*2^z=19*11^z solve for z

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Question 259892: use natural log to solve: 9*2^z=19*11^z solve for z
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
9*2^z = 19 * 11^z solve for z
:
ln(9) + ln(2^z) = ln(19) + ln(11^z)
:
2.197 + z*ln(2) = 2.944 + z*ln(11)
:
2.197 + .693z = 2.944 + 2.398z
:
2.197 - 2.944 = 2.398z - .693z
:
-.747 = 1.705z
z = %28-.747%29%2F1.705
z = -.438
;
;
Check on a calc: enter:
9 * 2^-.438 = 6.643
and
19 * 11^-.438 = 6.646, close enough