# How do I correctly use the fprinf function with the forward/backward elimination

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Jonas Morgner on 3 May 2022
How can I present may solution matrix I just calculated using the fprinf function?
My code so far:
%A
syms x1 x2 x3 % Defining the vairables
eqns = [x1 - 2*x2 + x3 == 0, % First equation
2*x2 - 8*x3 == 8, % Second equation
-4*x1 + 5*x2 + 9*x3 == -9]; % Third equation
[A] = equationsToMatrix(eqns) % Forming the coefficient matrix
% B
syms x1 x2 x3
eqns = [x1 - 2*x2 + x3 == 0,
2*x2 - 8*x3 == 8,
-4*x1 + 5*x2 + 9*x3 == -9];
[A,b] = equationsToMatrix(eqns) % Forming the augumented matrix
% C
A = [1 -2 1;
0 2 -8;
-4 5 9]
b = [0; 8; -9]
[L, U, P] = lu(A) % L = all multipliers, U = upper triangular matrix, P = row interchanges
y = L\(P*b) % Forward substitution
x = U\y % Backward substitution

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