lver_1_eq_2[0], solver_1_eq_2[1], solver_1_eq_2[2]);
    context.lineTo(x_to_client(ixy[0]), y_to_client(ixy[1]));
    var sxy = solve_2(solver_1_eq_1[0], solver_1_eq_1[1], solver_1_eq_1[2],  solver_1_eq_2[0], solver_1_eq_2[1], solver_1_eq_2[2]);
    context.lineTo(x_to_client(sxy[0]), y_to_client(sxy[1]));
    context.strokeStyle="#002200";
    context.lineWidth = 2;
    context.setLineDash([2, 2]);
    context.stroke();
    context.lineWidth = 1;
    context.setLineDash([]);
    context.closePath();

    