My Math Forum  

Go Back   My Math Forum > High School Math Forum > Elementary Math

Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion


Thanks Tree5Thanks
  • 1 Post By mathman
  • 1 Post By weirddave
  • 1 Post By skipjack
  • 1 Post By mathman
Reply
 
LinkBack Thread Tools Display Modes
July 8th, 2019, 11:14 AM   #1
Newbie
 
Joined: Feb 2018
From: California

Posts: 19
Thanks: 1

Placing Operation Signs to Make an Equation

Can you help me figure out this question?

Place the signs +. -, and = between these digits to make an equation. You can change the order of the signs, but you must use each sign only once.

4 8 3 3 6 9

Last edited by skipjack; July 9th, 2019 at 05:15 PM.
mjsilverfly is offline  
 
July 8th, 2019, 01:42 PM   #2
Global Moderator
 
Joined: May 2007

Posts: 6,805
Thanks: 716

Impossible. No matter how you group them, there will be an odd number of odd numbers on one side and and even number of odd numbers on the other. Using + or - will always end up netting a number with the same parity as the number of odds.
Thanks from mjsilverfly
mathman is offline  
July 9th, 2019, 02:01 AM   #3
Senior Member
 
Joined: Apr 2014
From: UK

Posts: 953
Thanks: 340

Did you mean 48 - 3 = 36 + 9 ?
Thanks from topsquark
weirddave is offline  
July 9th, 2019, 02:02 AM   #4
Global Moderator
 
Joined: Dec 2006

Posts: 20,919
Thanks: 2203

48 - 33 = 6 + 9 or 48 - 3 = 36 + 9
Thanks from topsquark
skipjack is offline  
July 9th, 2019, 08:29 AM   #5
Newbie
 
Joined: Feb 2018
From: California

Posts: 19
Thanks: 1

Oooooh! Yes!! Thank you, thank you!! Clever!
mjsilverfly is offline  
July 9th, 2019, 01:21 PM   #6
Global Moderator
 
Joined: May 2007

Posts: 6,805
Thanks: 716

Quote:
Originally Posted by mjsilverfly View Post
Oooooh! Yes!! Thank you, thank you!! Clever!
Your original statement was ambiguous.
mathman is offline  
July 9th, 2019, 11:19 PM   #7
Senior Member
 
Joined: Apr 2014
From: UK

Posts: 953
Thanks: 340

Quote:
Originally Posted by mathman View Post
Your original statement was ambiguous.
Given that you can use each sign only once and that the numbers must remain in the same order, there are a limited set of options, I'm not convinced it's ambiguous. If it is ambiguous, could you explain for those of us who may not have noticed?
weirddave is offline  
July 10th, 2019, 06:22 PM   #8
Global Moderator
 
Joined: May 2007

Posts: 6,805
Thanks: 716

Quote:
Originally Posted by weirddave View Post
Given that you can use each sign only once and that the numbers must remain in the same order, there are a limited set of options, I'm not convinced it's ambiguous. If it is ambiguous, could you explain for those of us who may not have noticed?
Allowing lumping. Must remain in same order?
Thanks from weirddave
mathman is offline  
July 10th, 2019, 11:50 PM   #9
Senior Member
 
Joined: Apr 2014
From: UK

Posts: 953
Thanks: 340

I see what I've done now. Given there are only 3 symbols which can be used only once, this would imply lumping of digits. I can't see anything which implies the digits must remain in the same order, I think I assumed that since we are told that the order of symbols may change, this means the numbers aren't otherwise that would have been mentioned too, but this isn't necessarily true. Thanks for making me think
weirddave is offline  
July 11th, 2019, 01:37 PM   #10
Global Moderator
 
Joined: May 2007

Posts: 6,805
Thanks: 716

Quote:
Originally Posted by weirddave View Post
I see what I've done now. Given there are only 3 symbols which can be used only once, this would imply lumping of digits. I can't see anything which implies the digits must remain in the same order, I think I assumed that since we are told that the order of symbols may change, this means the numbers aren't otherwise that would have been mentioned too, but this isn't necessarily true. Thanks for making me think
I missed the point of "only once" needed to force lumping.
mathman is offline  
Reply

  My Math Forum > High School Math Forum > Elementary Math

Tags
equation, equation in integers, make, operation, placing, signs



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Check if equation defines an operation on the set of integers. beesee Abstract Algebra 1 January 14th, 2017 07:37 AM
two equal signs in one equation darshanap Algebra 7 November 25th, 2016 02:09 AM
Please help me make an equation hhmathgeek Algebra 6 October 25th, 2015 05:09 PM
Placing integers icemanfan Math Events 2 September 26th, 2013 05:59 PM





Copyright © 2019 My Math Forum. All rights reserved.