Jawabanmu

2014-05-29T17:47:43+07:00
(x+3y)^3=(x+3y)(x+3y)(x+3y)
            =x^2+3xy+3xy+9y^2(x+3y)
            =x^2+6xy+9y^2(x+3y)
            =x^3+6x^2y+9xy^2+3x^2y+18xy^2+27y^3
           =x^3+9x^2y+27xy^2+27y^3

ga tau kalo salah .-.
2014-05-29T18:49:24+07:00
(x+3y)³
=(x+3y)(x+3y)(x+3y)
=(x²+3xy+3xy+9y²)(x+3y)
=x³+3x²y+3x²y+9xy²+3x²y+9xy²+9xy²+27y³
=x³+6x²y+9xy²+3x²y+18xy²+27y³
=x³+9x²y+27xy²+27y³
=x³+27y³+9x²y+27xy²