来自卢昱的问题
4xy+1-4x²-y²8x³+4x²-2x-1
4xy+1-4x²-y²
8x³+4x²-2x-1
1回答
2020-09-1801:16
4xy+1-4x²-y²8x³+4x²-2x-1
4xy+1-4x²-y²
8x³+4x²-2x-1
4xy+1-4x²-y²=1-(4x²+y²-4xy)=1²-(2x-y)²=(1+2x-y)(1-2x+y)8x³+4x²-2x-1=(8x³+4x²)-(2x+1)=4x²(2x+1)-(2x+1)=(4x²-1)(2x+1)=(2x+1)²(...