Barney has 14 dimes and quarters worth $2.15. write the system of equations
1 answer:
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Answer:
Step-by-step explanation:
I have no idea what formula that is you're using but the one I teach in both algebra 2 and in precalculus for continuous compounding is
where A(t) is the amount after the compounding, P is the initial investment, ee is Euler's number, r is the interest rate in decimal form, and t is the time in years. If our money doubles, we just have to come up with a number which will be P and then double it to get A(t). It doesn't matter what number we pick to double, the answer will come out the same regardless. I started with 2 and then doubled it to 4 and filled in the rest of the info given with time as my unknown:
Begin by dividing both sides by 2 to get
The only way we can get that t out of its current position is to take the natural log of both sides. Natural logs have a base of e, so
This is because they are inverses of one another. Taking the natural log of both sides:
Now divide by .062 to get
t = 11.2 years