Răspuns:
(a+3)²=a²+3²+6a
(2x-5)²=4x²-2·2x·5+5²
(a+√3)²=a²+3+2a√3
(a+2)(a-2)=a²-2²
(x-3)²=x²-6x+9
(x+y)(x-y)=x²-y²
