Help in method for solving simultaneous equations

I was wondering if anyone could help me solve 7 unknowns with 7 simultaneous equations in MATLAB, i understand the backslash method but with some equations being in a different format from one another I am stuck as to how to present them and solve them in MATLAB code.

have (1/4.5)(B) - (1/4.5)(B1) = F

(1/4.5)(B) - (1/4.5)(B2) = F4

(1/15)(B1) - (1/15) = F1

(1/11)(B2) - (1/11) = F2

(1/18)(B2) - (1/18) = F3

F = F1 + F2 + F3

F = F1 + F4

I need to find F1, F2, F3, F4, B, B1, B2

Where F is an inputted value at the start, so can be any value

Thank you!

Answer 1

[David Hill]

F=5;%whatever you want
A=[0 0 0 0 1/4.5 -1/4.5 0;0 0 0 -1 1/4.5 0 -1/4.5;-1 0 0 0 0 1/15 0;0 -1 0 0 0 0 1/11;0  0 -1 0 0 0 1/18;1 1 1 0 0 0 0;1 0 0 1 0 0 0];
b=[F;0;1/15;1/15;1/18;F;F];
x=A\b;%[F1,F2,F3,F4,B,B1,B2]