Question

If 2x + 3y = 12 and x y = 6 then find the value of: (8 x3 + 27 y3)


​

Answer 1

Answer:

(8 x³ + 27 y³) = 432

Step-by-step explanation:

(a+b)³ = a³+b³+3ab(a+b)

(8 x³ + 27 y³) = (2x) ³+(3y) ³

= (2x+3y)³-3(2x)(3y) (2x+3y)

= (12)³-3(36)(12)

= 1728-1296

= 432

Answer 2

Answer:

2x+3y=12 xy=6

8x^3+27y^3

=(2x)^3+(3y)^3

=>a^3+b^3=(a+b)(a^2+b^2−ab)

8x^3+27y^3

=(2x+3y)((2x)^2+(3y)^2−(2x)(3y))

=(12)[(2+3y)^2−12xy−6xy]

=(12)[(12)^2−18(6)]

=12[144−108]

=12×36

=432.

Step-by-step explanation:

Here is your answer..

Thanks