1.
Program NN;
Uses crt;
Var a,b: extended;
Begin
Clrscr;
Write('Nhap a,b: '); Readln(a,b);
Write('S = ',a*b:0:2);
Readln
End.
2.
Program NN;
Uses crt;
Var a,b: extended;
Begin
Clrscr;
Write('Nhap a,b: '); Readln(a,b);
If a=0 then
If b=0 then Write('VSN')
Else If b<>0 then Write('VN');
If a<>0 then Write('X = ',-b/a:0:2);
Readln
End.