Program GIAI_PHUONG_TRINH_BACII;Uses CRT;Var a,b,c,D,x,x1,x2: real;Begin Clrscr; Writeln('GIAI PHUONG TRINH BAC II: '); Writeln('-------------------------------------------'); Write('Nhap he so a='); readln(a); Write('Nhap he so b='); readln(b); Write('Nhap he so c='); readln(c); If a=0 then If b=0 then If c=0 then Writeln('Phuong trinh co vo so nghiem') Else Writeln('Phuong trinh vo nghiem') Else Writeln('Phuong trinh co mot nghiem: x=',-c/b: 4: 2) Else Begin D:=b*b-4*a*c; If D=0 then Writeln('Phuong trinh co nghiem kep: x=',-b/(2*a): 4: 2) Else If D<0 then Writeln('Phuong trinh vo nghiem') Else Begin x1:=(-b-sqrt(D))/(2*a); x2:=(-b+sqrt(D))/(2*a); Writeln('Phuong trinh co 2 nghiem la x1= ',x1:4:2 ,' va x2= ',x2:4:2); End; End;ReadlnEnd.