Question

18.11 2x + 3y = 12 and xy = 6, find the value of 8x^3+ 27y^3.​

Answer 1

Answer:

430 is the answer..

Step-by-step explanation:

2x + 3y = 12 and xy = 6

to find the value of 8x³ + 27y³

take cube of both sides

(2x+3y)³ = 12³. [ by identity (a+b)³ = a³ + b³ + 3ab(a+b) ]

(2x)³ + (3y³) + 3(2x)(3y)(2x+3y) = 1728

8x³ + 27y³ + 18xy(2x+3y) = 1728

8x³ + 27y³ + 18(6)(12) = 1728

8x³ + 27y³ + 1298 = 1728

8x³ + 27y³ = 1728 - 1298

[8x³ + 27y³ = 430]

HOPE IT HELPS YOU!!