Empty sym: 0-by-1.

Hi,

I'm trying to solve these four linear equation.

clear all;
clc;
syms a b c d e f g h z k l m n o p q v y 
eqn1 = a == y*(b*c+d*e+f*g+h*z);
eqn2 = k == y*(d*c+l*e+m*g+n*z);
eqn3 = o == y*(n*c+f*e+p*g+q*z);
eqn4 = v == y*(n*c+f*e+p*g+q*z);

sol = solve([eqn1, eqn2, eqn3, eqn4], [c, e, g, z]);
cSol = sol.c
eSol = sol.e
gSol = sol.g
zSol = sol.z

When it's run I got the solution as

Empty sym: 0-by-1.

Could you help me in figuring out this issue?

Thanks in advance

[Talal Salem]

Thank you

Answer 1

[Walter Roberson]

>> sol1 = solve([eqn1,eqn2,eqn3],[c,e,g])

sol1 = 

  struct with fields:

    c: [1×1 sym]
    e: [1×1 sym]
    g: [1×1 sym]

>> simplify(subs(eqn4,sol1))
 
ans =
 
v == o

Your equations are not independent; you cannot solve for all four of those particular variables at the same time.