计算输入a，b，c表达式
import java.util.Scanner;
public class Bds {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print(“输入a:”);
double a = scanner.nextDouble();
System.out.print(“输入b:”);
double b = scanner.nextDouble();
System.out.print(“输入c:”);
double c = scanner.nextDouble();
if (bb<4ac){
System.out.println(“根号下为负数”);
return;
}
double x;
x = Math.sqrt(bb-4ac);
System.out.println(“输出:”+(x-b)/(2*a));
}
}