Question

3. If (3x – 2y) = 5 and xy = 6, find the value of (27x3 - 8y3).​

Answer 1

Answer:(3x−2y)3=53 ⇒(3x)3−3×3x×2y(3x−2y)−8y3=125 ⇒27x3−18xy(3x−2y)−8y3=125 =27x3−18×6×5−8y3=125 ⇒27x3−8y3=125+540=665.

Answer 2

Step-by-step explanation:

(3x−2y)3=53 ⇒(3x)3−3×3x×2y(3x−2y)−8y3=125 ⇒27x3−18xy(3x−2y)−8y3=125 =27x3−18×6×5−8y3=125 ⇒27x3−8y3=125+540=665