solve with parameter

hello, i need to solve the equation with parameter. I have a problem with solution.

First, I wrote easy equation with parameter n.

syms x positive

n=2;

solve(x-n)     %equation has this form x-n=0

it works great

then I wrote

n=2;

solve(-n+x)

but the solution was not equal as in the first case.

I dont know what's wrong. Can you help me please. Thank you.

[Alexander]

I get the same result in both cases:

ans =

2

I have no idea what's wrong. Could you please share your results?

[Matus]

Sorry Alexander, I wrote a bad code. The problem was when I define

syms x

n=num2str(2);

solve(x-n) %result 2

solve(-n+x) %result 50

Answer 1

[Alexander]

Try to avoid num2str during calculations. This will convert the input into a string. A string is basically an array of character codes. If you do anymore calculations with it, it will be treated as an array of values, like in this example

>> A = num2str(12345);
>> A+0

ans =

      49    50    51    52    53

The number 50 stands for the character '2'. This is why -n results in -50 in your example above.

[Matus]

thank you