8x²-[-3x-(2x²-7x-5)+3]+4x怎么变号

来源：学生作业学帮网编辑：学帮网时间：2024/05/19 13:53:15

8x²-[-3x-(2x²-7x-5)+3]+4x
=8x²-(-3x-2x²+7x+5+3)+4x
=8x²-(-2x²+4x+8)+4x
=8x²+2x²-4x-8+4x
=10x²-8

8x²-[-3x-(2x²-7x-5)+3]+4x
=8x²-[-3x-2x²+7x+5+3]+4x
=8x²-[-2x²+4x+8]+4x
=8x²+2x²-4x-8+4x
=10x²-8