Question

simplify (X+y)^3 - (x-y)^3​

Answer 1

Answer:

2y³ + 6x²y

Step-by-step explanation:

Given : (x + y)³ - (x - y)³

Identity : (a + b)³ = a³ + b³ + 3a²b + 3ab²

(a - b)³ = a³ - b³ - 3a²b + 3ab²

→ [ (x)³ + (y)³ + 3(x)²(y) + 3(x)(y)² ] - [ (x)³ - (y)³ - 3(x)²(y) + 3(x)(y)² ]

→ [ x³ + y³ + 3x²y + 3xy² ] - [ x³ - y³ - 3x²y + 3xy² ]

→ x³ + y³ + 3x²y + 3xy² - x³ + y³ + 3x²y - 3xy²

→ 2y³ + 6x²y