Question

if 3 X + 2 Y is equal to 12 and x y is equals to 6 find the value of 27 x cube + 8 y cube

Answer 1

3X + 2Y = 12

CUBE BOTH SIDE
(3X+2Y)³ = (12)³

(A+B)³ = A³+B³+3AB(A+B)

27X³+8Y³+3(3X)(2Y)[3X+2Y] = (12×12×12)

27X³+8Y³+18(X)(Y)[12] = 1728

27X³+8Y³+18(6)(12) = 1728

27X³+8Y³+1296 = 1728

27X³+8Y³ = 1728-1296

27X³ +8Y³ = 432

SO THE VALUE OF 27X³+8Y³ IS 432

Answer 2

Given, 3x + 2y = 12
xy = 6
x = 6/ y
Putting the value of x
3(6/y) + 2y = 12
18/y + 2y = 12
18 + 2y square = 12 y
2ysquare -12y +10 = 0
Ysquare -6y +9 = 0
(Y - 3 )whole square
Y = 3
And x = 2
27xcube + 8ycube
27(2)cube + 8(3)cube
216+ 216
432