a.
program phuongt;
uses crt;
var x, y: real;
begin
clrscr;
write('Nhap x = '); readln(x);
write('Nhap y = '); readln(y);
writeln('P = ', 4*x*x*y/(x-y));
readln
end.
b.
program phuongt;
uses crt;
var x, y: real;
begin
clrscr;
write('Nhap x = '); readln(x);
write('Nhap y = '); readln(y);
writeln('S = ', x*x/(3*x+y));
readln
end.