uests[0] = 1; 
    } else {
        document.getElementById("reply_quest_1").innerHTML = "Excellent!";
        document.getElementById("buttons_quest_1").style.display = 'none';
        quests[0] = 1;
    }
    draw_plot_named('system_1', 0, 0, false);
}

function done_system_1_quest_2() {
    var xy = solve_2(system_1_eq_1[0], system_1_eq_1[1], system_1_eq_1[2], system_1_eq_2[0], system_1_eq_2[1], system_1_eq_2[2]);
    if(Math.abs(xy[0]) < 25 && Math.abs(xy[1]) < 25) {
        document.getElementById("rep