Question

if 3 x - 4 Y = 12 and XY= 6 find 27x^3 -64^3​

Answer 1

here is your answer. check it

Answer 2

Answer:

Using Identity : (a - b)³ = a³ - b³ - 3ab(a - b)

We get,

(3x - 4y)³ = (3x)³ - (4y)³ -3(3x)(4y)(3x - 4y)

⇒ 12³ = 27x³ - 64y³ - 36xy(12)

⇒ 1728 = 27x³ - 64y³ - 36(6)(12)

⇒ 1728 = 27x³ -64y³ - 2592

⇒ 27x³ - 64y³ = 1728 + 2592

⇒ 27x³ - 64y³ = 4320