cum se numesc aceste formule?:

1.(a+b)²=a²+2•a•b²
2.(a-b)²=a²=2•a•b+b²
3.(a-b)•(a+b)=a²-b²
4.(a+b+c)²=a²+b²+c²+2ab+2ac+2bl 5.a²+2ab+b²=(a+b)²
6.a²-2ab+b²=(a-b)²
7.a²-b²-(a-b)•(a+b)​