my matlab homework

GaussSeidel.m

clc; clear; close all; format('long', 'g');
fprintf("Gauss Seidel\n3x-0.1y-0.2z = 7.85 AND\n 0.1x+7y-0.3z = -19.3 AND\n 0.3x-0.2y+10z = 71.4 AND\n if error_x < 0.01 break; \n\n");
index = 1;
x(index) = 0;
y(index) = 0;
z(index) = 0;
error_x = 9999;

while error_x(index) >= 0.01
    x(index + 1) = (7.85 + 0.1 * y(index) + 0.2 * z(index)) / 3;
    y(index + 1) = (-19.3 - 0.1 * x(index + 1) + 0.3 * z(index)) / 7;
    z(index + 1) = (71.4 - 0.3 * x(index + 1) + 0.2 * y(index + 1)) / 10;
    error_x(index + 1) = abs(x(index + 1) - x(index)) / x(index + 1) * 100;
    error_y(index + 1) = abs(y(index + 1) - y(index)) / y(index + 1) * 100;
    error_z(index + 1) = abs(z(index + 1) - z(index)) / z(index + 1) * 100;
    index = index + 1;
end

disp('          x                   error(%)');
disp([x', error_x']);

disp('          y                   error(%)');
disp([y', error_y']);

disp('          z                   error(%)');
disp([z', error_z']);