pascal 求一元二次方程

PROGRAM Fangchen (Input,Output);
Var
A,B,C,D,E,F,G,H,I,J:Real;
Z,W:Char;
Begin
Repeat
Repeat
Write('a=');
Read(A);
Write('b=');
Read(B);
Write('c=');
Read(C);
Writeln('It is', A:7:3,'*X*X', ' +',B:7:3,'*X',' +',C:7:3,',',' is that right?');
Writeln('(y/n)');
Readln;
Readln(W)
Until W='y' ;
If A=0 Then Begin
D:=(-1)*C/B ;
Writeln('x=',D);
End ;
If (A=0) And (B=0)
Then Writeln('wrong input');
If (B*B-4*A*C)>0
Then If A<>0
Then Begin
E:=((-1)*B+Sqrt(B*B-4*A*C))/(2*A);
F:=((-1)*B-Sqrt(B*B-4*A*C))/(2*A);
Writeln('x1=',E:7:3