If 2x + 3y = 12 and xy = 6 then find 8x^3 + 27y^3

1.	If 2x + 3y = 12 and xy = 6 then find 8x^3 + 27y^3
Answer» 8x^3+ 27y^3 = (2x)^3 + (3y)^3 = ( 2x+3y)(2x^2 - 2x× 3y + 3y^2) = 12 ( 4x^2 - 6xy + 9y^2) = 12 ( 4x^2 - 6×6+9y^2) = 12 ( 2x^2 - 36 + 3y^2) = 12 ( 2x + 3y )^2 = 12 ( 12)^2 = 12× 12×12= 1728. Ans....

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