Linear System With Symbolic And Numerical Constants

How do I solve the following system on MATLAB?

The solution should be Fx1 = -1 and Fx5 = 0. Also, u2 = 0.005, u3 = 0.01, and u4 = 0.015.

Answer 1

[Mike]

I used:

syms f1 u2 u3 u4 f5
f=[f1;0;0;0;f5];
u=[0;u2;u3;u4;0.02];
k= [200 -200 0 0 0; -200 400 -200 0 0; 0 -200 400 -200 0; 0 0 -200 400 -200; 0 0 0 -200 200];
solve(f == k*u)

Yeilding:

f1: [1x1 sym]
f5: [1x1 sym]
u2: [1x1 sym]
u3: [1x1 sym]
u4: [1x1 sym]

To display the results use:

 ans.f1 
 ans.f5
 ans.u2

and so on.

Or:

syms f1 u2 u3 u4 f5
s=solve(0*0+0*u2+0*u3-200*u4+200*0.02==f5,0*0+0*u2-200*u3+400*u4-200*0.02==0,0*0-200*u2+400*u3-200*u4+0*0.02==0,-200*0+400*u2-200*u3+0*u4+0*0.02==0,200*0 -200*u2 + 0*u3 + 0*u4 +0.02*0==f1)

Answer 2

[Walter Roberson]

Use syms and set up a solve(A\b == x)