Erika is working on solving the exponential equation 50x = 17; however, she is not quite sure where to start. Using complete sentences, describe to Erika how to solve this equation.
@phi
you should use ^ to show exponents. like so: 50^x = 17 or the equation editor \[ 50^x = 17 \]
its 50^x by the way
yea sorry
exponents and logs go together , so you have to remember that (they "undo" the other) here is the rule you want to remember: \[ \log\left( a^b\right)= b \log(a) \]
ok
so do i put that it the form you showed?
you have an equation. if you do the "same thing" to both sides it will stay equal in this case, "take the log" of both sides for example , if you had 2^x = 8 take the log means write \[ \log(2^x) = \log(8) \]
log(50^x)=log(17)?
exactly. now on the left side, we use the "rule" (or property of logarithms) \[ \log\left( a^b\right)= b \log(a) \] to rewrite the left side can you do that ?
\[x \log 50 = \log 17\]
?
yes. looks good. even though it looks complicated, log(50) is a number we can divide both sides by the same number i.e. by log(50) \[ x \frac{\log(50)}{\log(50)} = \frac{\log(17)}{\log(50)}\] on the left side log50 divided by itself is 1 we get \[ x = \frac{\log(17)}{\log(50)}\]
so thats the final answer?
you could use a calculator, and find a decimal value. but yes, that is the answer. x is about 0.72423228 type into google: 50^0.72423228 = and you should get something close to 17
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