Use logarithms to solve 9^x=15
According to the rules of logarithms, when you take a log of something to the power of something, you multiply the log of the base by the power, so in this case, taking logs of both sides would give us
xlog9=log15
log9 is a number so we can divide both sides to give us
x=log15/log9=1.23 to 3sf
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