x²+3y-xy-3x= x³-x²-x+= x²-1-2xy+y= a²-b²-c²+2ab=

x²+3y-xy-3x= x³-x²-x+= x²-1-2xy+y= a²-b²-c²+2ab=
x²+3y-xy-3x= x³-x²-x+= x²-1-2xy+y= a²-b²-c²+2ab=

x²+3y-xy-3x= x³-x²-x+= x²-1-2xy+y= a²-b²-c²+2ab=
x²+3y-xy-3x= x³-x²-x+这里是加多少= x²-1-2xy+y= a²-b²-c²+2ab=,后面那里来的abc这些字母

题 不对呀

什么啊