(y+4)²=y²+2y·4+4²=y²+8y+16
(-3+a)²=(a-3)²=a²-6a+9
(2x-y)²=(2x)²-2·2xy+y²=4x²-4xy+y²
(-m-3n)²=(-m)²-2·(-m)·3n+(3n)²=m²+6mn+9n²
(⅖x²+½y)²=(⅖x²)²+2·⅖x²·½y+(½y)²=4/25 x⁴ + 2/5 x²y + 1/4 y²
(m²b⁴-na⁵)²​=(b⁴m²-a⁵n)²=b⁸m⁴-2a⁵b⁴m²n+a¹⁰n²