SOLUTION: How do I solve: 5= (1+r)^3 thanks! David

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Question 422644: How do I solve:
5= (1+r)^3
thanks!
David
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
5+=+%281%2Br%29%5E3
Exponential functions are equations where the variable is in the exponent. So your equation is not an exponential function. It is what is called a polynomial equation and I have changed the category of this problem to reflect it. Posting problems under the right category may lead to a quicker response from tutors because some tutors like doing certain types of problems and just look for problems within certain categories.

To solve your equation is fairly simple. We just have to find a way to strip away the exponent and the 1. We can eliminate the exponent by finding the cube root of each side:
root%283%2C+5%29+=+root%283%2C+%281%2Br%29%5E3%29
The cube root of the perfect cube simplifies:
root%283%2C+5%29+=+1%2Br
Now we just add -1:
-1+%2B+root%283%2C+5%29+=+r
And we're done!