Question

if 2x+3y=12 and xy = 6 find the value of 8x^3+27y^3

Answer 1

2x+3y=12

cube on both sides,

(2x+3y)^3 =12^3 

by the identity (a+b)^3= a^3 +b^3 +3ab(a+b)

here, 8x^3 + 27y^3 +3(6xy)(2x+3y) =12^3 

putting the values which are given ,

8x^3 +27y^3 +3*(6*6)(12) = 1728

8x^3 + 27y^3 +1296 = 1728

8x^3 +27y^3 = 1728-1296

8x^3 +27y^3 =432

Answer 2

Answer:

Step-by-step explanation:

432 is the correct answer