var
Xnach, Xkon, Dx, a,b,c, F :real;
begin
write('vvedite Xnach = '); readln(Xnach);
write('vvedite Xkоn = '); readln(Xkon);
write('vvedite dx = '); readln(dx);
write('vvedite a = '); readln(a);
write('vvedite b = '); readln(b);
write('vvedite c = '); readln( c );
while Xnach<Xkon begin
if (a < 0) and (c <> 0) then F:= a*Xnach*Xnach + b*Xnach+c
else
if (a > 0) and (c = 0) and (Xnach <> c) then F:= (— a)/(Xnach -c)
else