Use 2,3,7,8 to Write Math Expressions from 1 - 50Date: 10/03/2004 at 11:46:16 From: ejae Subject: using 2,3,7,8 find numbers 44 and 46 Using 2,3,7,8, find expressions for the numbers 44 and 46, such as 47 = (7 + 8) x 3 + 2. I've tried all possible equations but can't figure out the right one. I have done from 1 to 50 except these 2 numbers left. Date: 10/05/2004 at 03:16:43 From: Doctor Korsak Subject: Re: using 2,3,7,8 find numbers 44 and 46 Hello Ejae, There is a neat free download PC program, 200Up, which generates all possible numbers using any specified four numbers. You can download it here: http://ourworld.compuserve.com/homepages/DavidandPenny/200Up.htm I just ran it for your case, and it got 44 = (7*(3/2))*8 but it failed to get a representation of 22, 32, 42 and 46 when allowed to use only * / + - operators. After adding the option of square roots, it got all but 22 and 46: 32 = 2 * sqrt(7 - 3)*8 42 = (3 / sqrt(2/8))*7 and then when I enabled using exponentiation x^y it got the rest of them: 22 = sqrt(sqrt(7 - 2)^8 - 3 46 = sqrt(7^(8/2)) - 3 Keep in mind that the idea behind this sort of assignment or challenge is to give you practice in thinking mathematically. Obviously, using this software package removes much of that benefit. But if you have given a good effort and are stuck, it's a nice way to pick up those last few numbers! Please contact Dr. Math if you need further help. - Doctor Korsak, The Math Forum http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2015 The Math Forum
http://mathforum.org/dr.math/