How to solve equations in c#

i don't see you have been declare variable x, y
so that the compiler throws that error

to solve that error, you can declare x, y variable inside your function like:

int x = 100; // value 100 is an example 
int y = 100; // value 100 is an example 
int x0 = 5;
int x1 = 2;

....

or write an function like:

public int MyEquation(int x)
{
     int y;

     // here is your code

     return y;
}

You need to tell us what exactly you are trying to acheieve here. With the given information, this can be very easily done through String.Format. But does it help you? I think it will not.

int x0 = 5;
int x1 = 3;
string originalString = "y = (x-{0})/({1})";

string updatedString = string.Format(originalString, x0, (x0 - x1));

You need to implement a parser of your own which could solve the equations. One needs to be well aware of your requirements to help you out. Search google for "C# Equation Parser". It may give you some ideas to start with.

of course it will ,you haven't declared x,I see you have declared x0 and x1 only , the compiler won't understand what you want till you tell it


the solution of this type of problem is treating with variables of an equation (not of program asp...etc ) as string and using post-fix notation to solve it with some change that you will determine the variable as it is with out value
e.g
(X-x0)/(x0-x1)---post-fix--> Xx0-x0x1-/
the X means that it's variable of an equation solve it using stack I'll post the solution later.....

Programming languages (usually) don't directly support symbolic algebra manipulation, have a look at Computer Algebra Systems[^] page at Wikipedia to get an idea about what you are trying to do.

That's because you haven't declared x yet.

(Engineers shouldn't be allowed to do their own programming.)