Question

simply (2x-5y)³ - (2x+5y)³​

Answer 1

We have the formula that

(a−b)3 = a3 − b3 − 3ab(a−b)

(a+b)3 = a3 + b3 + 3ab(a+b)

The given question is (2x−5y)3 − (2x+5y)3

= (8x3 − 125y3 − 30xy(2x−5y)) − (8x3 + 125y3 + 30xy (2x+5y) )

= 8x3 − 125y3 − 60x2y + 150xy2 − 8x3 − 125y3 − 60x2y

− 150xy2

= −250y3 − 120x2y

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Answer 2

Answer:

Your answer is:-

Step-by-step explanation:

(2x -5y)^3 – (2x + 5y)^3 = [(2x)^3 – (5y)^3 – 3(2x)(5y)(2x – 5y)]

-[(2x)3 + (5y)3 + 3(2x)(5y)(2x+5y)]

[using identity, (a – b)^3 = a^3 -b^3 – 3ab  and (a + b)^3 =a^3 +b^3 + 3ab] = (2x)^3 – (5y)^3 – 30xy(2x – 5y) – (2x)^3– (5y)^3 – 30xy (2x + 5y)

= -2 (5y)^3 – 30xy(2x – 5y + 2x + 5y)

= -2 x 125y^3 – 30xy(4x) = -250y3 -120x^2y