Solving Equality w/ 2,3,4,5,+,=: Two Ways?

  • Context: High School 
  • Thread starter Thread starter T@P
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the challenge of creating an equality using the numbers 2, 3, 4, and 5, along with the operators + and =, with the stipulation that each number and operator must be used only once. Participants explore potential solutions and the constraints of the problem.

Discussion Character

  • Exploratory, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant suggests the equation 2 + 5 = 3 + 4 as a potential solution, noting that there are infinitely many ways if the number of symbols is not restricted.
  • Another participant clarifies that the numbers and operators can only be used once, disqualifying previous suggestions like 3 + 4 = 2 + 5.
  • A participant questions whether writing two numbers next to each other could imply multiplication, proposing an equation format that includes multiplication.
  • One participant presents the equation 4 + 5 = 3² as their first attempt, while another expresses agreement but seeks additional solutions.
  • Another participant argues that given the constraints of the operators and digits, there may be limited possibilities for valid equations.
  • Concerns are raised about the use of more than two operators in proposed equations, suggesting that using a two-digit number might be necessary but would not yield a valid equation.
  • Some participants discuss the interpretation of notation, such as whether writing 2^3 counts as using the numbers 2 and 3 without counting operators.

Areas of Agreement / Disagreement

Participants generally agree on the constraints of the problem but disagree on the interpretation of how to use the numbers and operators effectively. There is no consensus on whether additional solutions exist beyond those already proposed.

Contextual Notes

The discussion is limited by the specific requirement that each number and operator can only be used once, which constrains the possible equations significantly. There are also ambiguities regarding notation and the interpretation of adjacent numbers.

T@P
Messages
274
Reaction score
0
how can you write an equality ONLY using 2, 3, 4, 5, +, and =? note ALL must be used. I have done this problem and it is easy but i was wondering if there are two ways to do it. Any ideas?
 
Mathematics news on Phys.org
2 + 5 = 3 + 4

There are infinitely many ways of doing it, providing you don't limit the number of symbols used. I believe this, and rearrangements of this, is the simplest.

2 + 3 + 4 = 5 + 4

2 + 2 + 2 + 3 = 4 + 5

2 + 5 = 3 + 4 = 2 + 2 + 3

...

ad infinitum
 
i believe i misstated the question. the numbers 2 3 4 and 5 can be used only once as with the = and + sign. sorry about that so

3 + 4 = 2 + 5 would NOT work because you would be using the plus sign twice
 
Hmmm, would having two numbers next to each other count as multiplying? For instance 3x is seen as multiplying 3 times the value of x, so could the answer be written 5 + 3 = 2 4 with the statement that 2 and 4 are being multiplied?
 
first attempt: 4+5=3²
 
thats what i got too :) but do yuo know any other ways?
 
i don't think that there are any more...
look:
we have '+' and '=' operators, thus 3 free slots that are to be filled with at least one digit each. so 3 of 4 given didits are bound. that is we have only one free digit left. now, there are not that much possibilities in choosing the numbers for each slot AND choosing the position for the "free" digit. So we can just check all the possibilites for consistency...
 
hemmul said:
first attempt: 4+5=3²

can this equation not be written more appropriately as

4+5=3^2

thus we are using more than 2 operators. in fact in this case it is not possible to get an equation as with 2 operators we can use only 3 numbers...


thus the only way of using 4 digits would be if we use a 2 digit no. like 24, or 35, or something like that,, but then it is not possible to get any equation. :smile:
 
im assuming that writing 2^3 on paper by hand would just be the numbers 2 and 3
if i am not counting operators, just what's written :)

so anyone know another way? i believe its impossible but i am not sure...
 
  • #10
T@P said:
im assuming that writing 2^3 on paper by hand would just be the numbers 2 and 3
if i am not counting operators, just what's written :)
In that case 2 4 should be ok also.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 2 ·
Replies
2
Views
6K
  • · Replies 59 ·
2
Replies
59
Views
232K
  • · Replies 38 ·
2
Replies
38
Views
7K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K