Trying to find an Equation: 13.5,25.1,29.5,25.3=-7.4

[Benny@018]

Hello, am trying to find out answer from given values , well it seem complicated and well tangled for to solve it if any one can help with it , it would be a great help.
problem is I have value 13.5,25.1,29.5,25.3=-7.4, where as by using mathematical expressions we could 13.5-25.1+29.5-25.3=-7.4. But my question is how can I find the answer with only three values like 13.5,25.1,29.5 by using these three values is there a possibility to find the answer -7.4?
Well I have tried finding the way but not quite successful. another way 29.5-4.2 gives 25.3 by which way I could atleast get 4.2.

13.5,25.1,29.5,x=y

any formula to slove this ??

 

[Dr.Peterson]

Hello, am trying to find out answer from given values , well it seem complicated and well tangled for to solve it if any one can help with it , it would be a great help.
problem is I have value 13.5,25.1,29.5,25.3=-7.4, where as by using mathematical expressions we could 13.5-25.1+29.5-25.3=-7.4. But my question is how can I find the answer with only three values like 13.5,25.1,29.5 by using these three values is there a possibility to find the answer -7.4?
Well I have tried finding the way but not quite successful. another way 29.5-4.2 gives 25.3 by which way I could atleast get 4.2.

13.5,25.1,29.5,x=y

any formula to slove this ??

As I understand it, you are given some set of numbers (the four numbers 13.5, 25.1, 29.5, 25.3 in the first example, or 13.5, 25.1, 29.5 in the second), and you want to find a way to combine them using only addition and subtraction in order to obtain a given number (-7.4 in both examples).

It should be obvious that in general it would be impossible; for example, with three given numbers, if you have to use all three numbers there are only 8 different numbers that can be obtained, corresponding to signs +++, ++-, +-+, +--, -++, -+-, --+, ---. (If you can exclude some numbers, then there are 26 possible results.) If the goal number is not one of those, then you can't get it.

The way to find the answer is to try all possibilities. List them all (using the signs I listed above), and see if any of the results is -7.4.

If you have more numbers, there are shortcuts you could take to avoid having to try everything, but this is all you need here.

But I don't know what you mean by "13.5,25.1,29.5,x=y". What does this have to do with the problem? Are both x and y variable, rather than the result having to be given?

Maybe if you tell us what your real goal is (why you are asking), we can change the problem to something that can be solved.

 

[Benny@018]

As I understand it, you are given some set of numbers (the four numbers 13.5, 25.1, 29.5, 25.3 in the first example, or 13.5, 25.1, 29.5 in the second), and you want to find a way to combine them using only addition and subtraction in order to obtain a given number (-7.4 in both examples).

It should be obvious that in general it would be impossible; for example, with three given numbers, if you have to use all three numbers there are only 8 different numbers that can be obtained, corresponding to signs +++, ++-, +-+, +--, -++, -+-, --+, ---. (If you can exclude some numbers, then there are 26 possible results.) If the goal number is not one of those, then you can't get it.

The way to find the answer is to try all possibilities. List them all (using the signs I listed above), and see if any of the results is -7.4.

If you have more numbers, there are shortcuts you could take to avoid having to try everything, but this is all you need here.

But I don't know what you mean by "13.5,25.1,29.5,x=y". What does this have to do with the problem? Are both x and y variable, rather than the result having to be given?

Maybe if you tell us what your real goal is (why you are asking), we can change the problem to something that can be solved.

Thank you, Dr. Peterson , its not only about combining values with addition and subtraction but with any possible way I would like to know.

The reason why am asking this kind off question is I have obtained these values from my research and trying to find out the next move , and I have split the values into group of three or four to find out next values.. values in the data are 34.9,20.9,13.5,25.1,29.5,25.3.

If the values are in group of four 34.9,20.9 ,13.5,x , in the place of X the value should be 25.1( it should get with calculation),t

he same way the next group with values 20.9,13.5,25.1,X at here in the value of X has to be 29.5. in this way the first value cuts down and X value adds up in the group of three values to bring fourth value..

The reason why I gave the 13.5-25.1+29.5+x=y Because 13.5-25.1+29.5-25.3=-74 In this case both the x and y are unknown for me, as I have not found a way to get 25.3. in this way Ito find out the next value I have asked.

Actually I could able to find out the value with combination but my problem is for every new group same combination is not working .

Basically I need one formula to work with all groups . Is there any way where I could get formula for all.

I hope you have understood my problem now.​

Thank you