How to keep results on the same line in console in java?

Question

I've been working on this assignment for my programming class where I have to write a program to solve a quadratic equation in the format of a^2+bx+c=0. I worked with a classmate to figure out how to solve the actual problem, but when I try to run it through our testing software it tells me I need the results in the console to all be on the same line.

This is the error it gives:

I'll attach my code at the bottom, I'm a beginner and was pretty much guided through this by my classmate so I'm still trying to figure things out. Thanks so much in advance!

import java.util.Scanner;

// TODO: document this class
public class PA2a {

    // TODO: document this function
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter a b c: ");
        
        double a,b,c, root_1, root_2;
        a = input.nextDouble();
        b = input.nextDouble();
        c = input.nextDouble();
        
        double discriminant = b * b - 4 * a * c;
        
        if(discriminant > 0) {
            root_1 = (-b + Math.sqrt(discriminant)) / (2 * a);
            root_2 = (-b - Math.sqrt(discriminant)) / (2 * a);
            if(root_1 < root_2)
                System.out.printf("Roots: %.2f, %.2f", root_1, root_2);
            else
                System.out.printf("Roots: %.2f, %.2f", root_2, root_1);
                
        }
        
        else if (discriminant == 0) {
            root_1 = root_2 = -b / (2*a);
            System.out.printf("Root: %.2f", root_1);
            
        }
        
        else {
            System.out.print("Roots: imaginiary");
            
        }
        input.close();
    }

}