计算下列各式：①(x+2y+z )² ②（2x-3y-4z）² ③（2x-y+3）²

计算下列各式：①(x+2y+z )² ②（2x-3y-4z）² ③（2x-y+3）²
计算下列各式：①(x+2y+z )² ②（2x-3y-4z）² ③（2x-y+3）²

计算下列各式：①(x+2y+z )² ②（2x-3y-4z）² ③（2x-y+3）²
x2+4y2+z2+4xy+4yz+2xz
4x2+9y2+16z2-12xy-16xz+24yz    
4x2+y2+9-4xy+12x-6y