Math, asked by artisharadtripathi, 11 months ago

If 2x-3y=10 and xy=16;find the value of
8x^3-27y^3

Answers

Answered by LovelyG

2x - 3y = 10

On Cubing both sides -

(2x - 3y)³ = (10)³

⇒ (2x)³ - (3y)³ - 3 * 2x * 3y ( 2x - 3y) = 1000

⇒ 8x³ - 27y³ - 18 xy ( 10 ) = 1000

⇒ 8x³ - 27y³ - 18 * 16 * 10 = 1000

⇒ 8x³ - 27y³ - 2880 = 1000

⇒ 8x³ - 27y³ = 1000 + 2880

⇒ 8x³ - 27y³ = 3880

happy303: so

happy303: 3 × 16 ( 10 ) thats it

happy303: i guess ur answer is wrong

LovelyG: 3ab = 3 * 2x * 3y = 18xy

LovelyG: The answer is absolutely correct!

LovelyG: Please be sure before reporting the answer. It was correct.

happy303: already ab is given as 16

LovelyG: xy is given 16, but a = 2x and b = 3y

LovelyG: (a-b)³ = a³ - b³ - 3ab(a-b)

LovelyG: In place of a, you have to put 2x and in place of b, you have to put 3y

Answered by happy303

hey the answer is. ....

hope it helps uu frnd.

Attachments:

LovelyG: Wrong Formula used

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