help --- symbolic expression or function

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justlikethat
justlikethat 2021-6-11
评论： justlikethat 2021-6-11
I've created a code for the symbol variables.
But I'm very embarrassed because the same error keeps coming out.
I'd appreciate it if you could tell me the solution.
syms x y z
one = sym('3*x +2*y - z = 10');
two = sym('-x + 3*y + 2*z = 5');
three = sym('x -y - z = -1');
[x,y,z] = solve(one,two,three)
error messeage ---->
The text vector and string type of the first argument can only specify variables or numbers. Use 'str2sym' to evaluate the string type and the text vector representing the symbol expression.
Error occurred: sym>tomupad (Line 1296)
S = convertChar(x);
Error occurred: sym (Line 234)
S.s = tomupad(x);
Error occurred: symsolve (Line 2)
one = sym('3*x +2*y - z == 10');
My grammar may be wrong because I am not good at English. Thank you!

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采纳的回答

Walter Roberson
Walter Roberson 2021-6-11
Ran in:
The code you are using has not been valid since about R2017b.
syms x y z
one = str2sym('3*x +2*y - z = 10');
two = str2sym('-x + 3*y + 2*z = 5');
three = str2sym('x -y - z = -1');
[x,y,z] = solve(one,two,three)
x = 
y = 
5
z = 
but better would be
syms x y z
one = 3*x +2*y - z == 10;
two = -x + 3*y + 2*z == 5;
three = x -y - z == -1;
[x,y,z] = solve(one,two,three)
x = 
y = 
5
z = 

更多回答（1 个）

KSSV
KSSV 2021-6-11
syms x y z
one = 3*x +2*y - z == 10;
two = -x + 3*y + 2*z == 5;
three = x -y - z == -1 ;
s = solve({one,two,three},x,y,z) ;
[s.x s.y s.z]

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