A)
(x + 2)³ = x³ + 3 * x² * 2 + 3 * x * 2² + 2³ = x³ + 6x² + 12x + 8
B)
(3x - 5y)³ = (3x)³ - 3(3x)²(5y) + 3(3x)(5y)² - (5y)³ = 27x³ - 135x²y + 225xy² - 125y³
C)
(x - 3y)³ + (y + 2)³ + (x + y - 2)² =
= x³ - 3(x²)(3y) + 3(x)(3y)² - (3y)³ +
+ y³ + 3(y²)(2) + 3(y)(2)² + (2)³ +
+ x² + xy - 2x + xy + y² - 1y - 2x - 2y + 4 =
=x³ - 9x²y + 27xy² - 8y³ + 6y² + 12y + 12 + x² + 2xy - 4x + y² - 3y