Question

2)(x-y)³-(x+y)³
3)(2a+3b)³-(2a-3b)³

Answer 1

2) (x - y)³ - (x + y)³ = x³ - y³ - x³ + y³= x³ - x³ - y³ + y³ = 0

3) (2a + 3b)³ - (2a - 3b)³= 8a³ + 27b³ - 8a³ - 27b³ = 8a³ - 8a³ + 27b³ - -27b³ = 0