Question

x-y=3 then value of x^3-y^3-9xy​

Answer 1

Step-by-step explanation:

x³-y³ = (x-y)*(x²+xy+y²)

x - y = 3, then (x-y)² = 9, thus x²-2xy+y² = 9.

x²+xy+y² = x²-2xy+y² + 3xy, so, x²+xy+y² = 9 + 3xy.

Back to our question: we have now the value of x-y and x²+xy+y².

(x-y)*(x²+xy+y²) - 9xy = 3 * (9 + 3xy) - 9xy = 27 + 9xy - 9xy = 27.

Answer 2

Answer:

27

Step-by-step explanation:

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