solve LGS dumb

public static double[] solveDumb(double[][] A, double[] b) {
    final double speed = 0.1;
    double[] x = DoubleStream.generate(() -> 0).limit(b.length).toArray();
    boolean done = false;
    outer:
    while (!done) {
        done = true;
        for (int i = 0; i < b.length; ++i) {
            for (int j = 0; j < b.length; ++j) {
                double result = 0;
                for (int k = 0; k < b.length; ++k)
                    result += A[i][k] * x[k];
                double error = b[i] - result;
                if (!isZero(error) && !isZero(A[i][j])) {
                    done = false;
                    x[j] += speed * error / A[i][j];
                }
            }
        }
    }
    return x;
}