1.

If 3x-2y=11 and xy=12 find the value of 27x whole cube-8y whole cube

Answer»

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Here is your answer...✌

GIVEN THAT,

3x - 2Y = 11 -----(1)

xy = 12 -----(2)

Cubing both sides in eq(1)
We get

(3x - 2y)³ = 11³

(3x)³ - (2y)³ - 3(3x)(2y) (3x - 2y) = 11³

27x³ - 8y³ - 18xy × 11 = 11³ __ [from (1)]

27x³ - 8y³ - 18×12×11 = 11³ __ [from(2)]

27x³ - 8y³ = 11³ + 18×12×11

= 11 (11² + 18×12)

= 11 (121 + 216)

= 11 × 337

= 3707

Hence,

27x³ - 8y³ = 3707



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