1、3x²-2x+4xy+y²-(5x²-3xy)=3x²-2x+4xy+y²-5x²+3xy=-2x²+7xy-2x+y²
2、(A+B)-[2A-(C-3B)]=A+B-[2A-C+3B]=A+B-2A+C-3B=C-A-2B
=2X-3-(6X²-4X-2)-2(-2X²+5)
=2X-3-6X²+4X+2+4X²-10
=-2X²+6X-11
1、3x²-2x+4xy+y²-(5x²-3xy)=3x²-2x+4xy+y²-5x²+3xy=-2x²+7xy-2x+y²
2、(A+B)-[2A-(C-3B)]=A+B-[2A-C+3B]=A+B-2A+C-3B=C-A-2B
=2X-3-(6X²-4X-2)-2(-2X²+5)
=2X-3-6X²+4X+2+4X²-10
=-2X²+6X-11