3)
Program GIAI_PHUONG_TRINH_BAC_NHAT;
Var a,b,x:real;
Begin
Clrscr;
Writeln('GIAI PHUONG TRINH BAC NHAT: AX + B=0');
Writeln('------------------------------------------------------------');
Write ('Nhap a= '); readln(a);
Write ('Nhap b= '); readln(b);
If(a=0) then If(b=0) then Writeln(' Phuong trinh co vo so nghiem')
Else writeln(' Phuong tring vo nghiem')
Else Writeln('Phuong trinh co nghiem x=',-b/a:4:2);
Readln;
End.