câu 1
2xy+SQR(x) =>0
SQR(m+n) <> SQR(M) +SQR(N)
Câu 2
uses crt;
var a,b,c:integer;
begin
clrscr;
writeln('nhap canh day thu nhat');readln(a);
writeln('nhap canh day thu hai');readln(b);
writeln('nhap chieu cao'); readln(c);
writeln('dien tich hinh thang');
writeln((a+b)*c,'/',2,'=',((a+b)*c)/2:5:2);
readln;
End.