If #216 * 3^(2x)-73*3^x-3=0# and #u=3^x#, what is the value of #u#?
2 Answers
Explanation:
If
then
becomes
Using the quadratic formula (and a calculator)
or
...but if
and therefore the negative version is extraneous,
leaving only
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As a bonus we could find the value of
If
then
then using a calculator
Explanation:
The equation is in the form,
Since it is difficult to use
Once we solve for u, we will then replace u with 3^x and find the value of x.