solve each equation?
hmmm-well Suggested solution
log3^n+log9=log69
log3^n=log69-log9
n=(log69-log9)/log3
find n then round up
"Solve each equation. Round your answers to the nearest ten-thousandth." (These are my directions)
Here is the equation: 3^n + 9 = 69
How do I solve this getting the answer asked for?
2 answers
You cannot take log of individual terms, you have to take log of both sides.
i.e. log (3^n + 9) = 69
but , why not just do this:
3^n = 60
now log both sides, and use log rules:
n log3 = log60
n = log60/log2 = appr 3.727
check:
3^3.727 + 9 = 69.01100 , close enough to 69
if you meant:
3^(n+9) = 69
(n+9)log3 = log 69
n+9 = log 69/log3
n = log69/log3 - 9
i.e. log (3^n + 9) = 69
but , why not just do this:
3^n = 60
now log both sides, and use log rules:
n log3 = log60
n = log60/log2 = appr 3.727
check:
3^3.727 + 9 = 69.01100 , close enough to 69
if you meant:
3^(n+9) = 69
(n+9)log3 = log 69
n+9 = log 69/log3
n = log69/log3 - 9
2 answers