How to find Symbolic solution of a system of linear equations with specific accuracy

[Nataly_S]

 

Hello.
Could someone help me, please, with this task? An error while trying to find Symbolic solution of a system of linear equations with specific accuracy. What I should do make it done?

[Werner_E]

Always additionally attach the worksheet itself.

Chances are that at least one of the variables you solve for was already assigned a value before. Try typing w:=w, etc. before trying to symbolically solve.

[Nataly_S]

Thank you.

[LucMeekes · Accepted solution]

You should definitely attach your worksheet, because this simply works:

The other thing is: Why do you insist on a symbolic solution for a pure numerical problem?

The symbolic problem would be:

with as solution:

(That's not a grey line, but a very long expression, zoomed out)

The four individual answers are:

Success!
Luc

[Nataly_S]

Thank you. I opened new document and made copy past all equation and finally it works. I don't know why it was not worked on previous worksheet. Maybe because I have several worksheet pages (I made laboratory tasks).

[Werner_E]

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@Nataly_S wrote:

Thank you. I opened new document and made copy past all equation and finally it works. I don't know why it was not worked on previous worksheet. Maybe because I have several worksheet pages (I made laboratory tasks).

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As already written I guess that in your original sheet you already had assigned a value to one of the variables w, x, y or z. In this case the symbolics throws the error shown in your pic. Solution is to make this variable unknown to the symbolic engine again by typing w:=w  x:=x, etc.