1.-8a³b²÷8a³b²=-1
2.-10x³+15x²-20x+4x³+15x=-6x³+15x²-5x
3.麻烦
4.(x-y)²-z²省略
[x²-y²-x²-y²-2xy-2yx+2y²)]÷(-2y)
=-4xy÷(-2y)
=2x
把x=5代入上式,可得
2x=10
1.-8a³b²÷8a³b²=-1
2.-10x³+15x²-20x+4x³+15x=-6x³+15x²-5x
3.麻烦
4.(x-y)²-z²省略
[x²-y²-x²-y²-2xy-2yx+2y²)]÷(-2y)
=-4xy÷(-2y)
=2x
把x=5代入上式,可得
2x=10