Solve for x: 131,072 = 2^xDate: 09/12/2001 at 01:35:52 From: Niki Thiessen Subject: Exponents How do I solve the following equation for x: 131,072 = 2^x I know the answer is 17, but can't remember how to solve it. Date: 09/12/2001 at 12:09:57 From: Doctor Peterson Subject: Re: Exponents Hi, Niki. It depends on what tools you have. With a calculator (so I can handle logarithms), I would take the log of both sides and solve for x by dividing. By hand, I would just square 2 repeatedly until I got near 131,072, and then find what additional doublings it takes: 2^2 = 4 2^4 = 4^2 = 16 2^8 = 16^2 = 256 2^16 = 256^2 = 65536 The next squaring would take me too far, so I divide 131072 by 65536 and find that I just need to multiply by 2 one more time: 131072 = 2 * 2^16 = 2^17 - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/