(x+y+z)³={(x+y)+z}³=(x+y)³+3(x+y)²z+3(x+y)z²+z³=x³+3x²y+3xy²+y³+3z(x²+2xy+y²)+3xz²+3yz²+z³=x³+y³+z³+3x²y+3xy²+3zx²+3y²z+3xz²+3yz²+6xyz(^^잘알아보길)
당신은 어느 그룹입니까?