Question

write the following in expanded form
(2x-5y)³-(2x+5y)³​

Answer 1

Answer:

use the identity(a)^3 - (b)^3

Step-by-step explanation:

brainliest plz

Answer 2

✣ To expand:-

• (2x-5y)³-(2x+5y)³

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$\</u><u>l</u><u>a</u><u>r</u><u>ge\bf\underline\</u><u>b</u><u>l</u><u>u</u><u>e</u><u>{</u><u>Solu</u><u>tioN</u><u>}$

By using two identities:-

◆(a + b)³ = a³ + b³ + 3ab ( a + b)

• Above identity in (2x+5y)³

◆(a - b)³ = a³ - b³ - 3 ab ( a - b)

• Above identity in (2x-5y)³

So,

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

⇒8x³ - 125y³ - 30xy ( 2x - 5y) - 8x³ + 125y³ + 30xy ( 2x + 5y)

⇒8x³ - 125y³ - 60x²y + 150xy² - 8x³ + 125y³ + 60x²y + 150xy²

⇒8x³ - 8x³ - 125y³ + 125y³ - 60x²y + 60x²y + 150xy² + 150xy²

⇒300xy²

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More identities :-

• (a + b )² = a² + b² + 2ab
• (a - b)² = a² + b² - 2ab
• (a + b) (a - b) = a² - b²