Symbolic solution to a system of equations

Can Matlab solve a system of equations like a+b=c, b=2c symbolically for b and c? The output should be c=-a, b=-2a

Answer 1

[Ameer Hamza]

In MATLAB you solve it like this using symbolic variables and solve function()

syms a b c

eq1 = a+b==c;
eq2 = b==2*c;

sol = solve([eq1 eq2])

Result:

>> sol.b
ans =
-2*a
 
>> sol.c
ans =
-a

[Aleem Andrew]

Thank you

[Ameer Hamza]

Glad to be of help.

[Altug Bilge]

If you then want to assign a value for a and calculate b or c, how would you do that?

[Ameer Hamza]

You can use subs() function

b_val = subs(sol.b, a, 5); % substitute a=5

[Altug Bilge]

Thank you so much!

Answer 2

[David Hill]

syms a;
[1,-1;2,-1]\[a;0];