约分如下：①2b-ab/a²-2a②（a+b）²-c²/a+b+c③6x²y+2xy²/9x²-y²④16a⁴b²c^5/12a³b⁴c²

约分如下：①2b-ab/a²-2a②（a+b）²-c²/a+b+c③6x²y+2xy²/9x²-y²④16a⁴b²c^5/12a³b⁴c²
约分如下：
①2b-ab/a²-2a
②（a+b）²-c²/a+b+c
③6x²y+2xy²/9x²-y²
④16a⁴b²c^5/12a³b⁴c²

约分如下：①2b-ab/a²-2a②（a+b）²-c²/a+b+c③6x²y+2xy²/9x²-y²④16a⁴b²c^5/12a³b⁴c²
①(2b-ab)/(a²-2a)
=-(ab-2b)/(a²-2a)
=-b(a-2)/[a(a-2)]
=-b/a
②[（a+b）²-c²]/(a+b+c)
=(a+b+c)(a+b-c)/(a+b+c)
=a+b-c
③(6x²y+2xy²)/(9x²-y²)
=2xy(3x+y)/[(3x-y)(3x+y)]
=2xy/(3x-y)
④16a⁴b²c^5/12a³b⁴c²
=16ac³*a³b²c²/(12a³b²c²*b²)
=16ac³/(12b²)
=4ac³/(3b²)