Question

if 2x +3y=13 and xy=6,find the value of 8x^3+27y^3

Answer 1

(2x+3y)=13

whole quebe both side

(2x+3y)³=13³

8x³+27y³+3.2x.3y.(2x+3y)=2197

8x³+27y³+18×6(13)=2196

8x³+27y³=2196-1404=792