约分 （6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²)（6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²) (16b²y²)/(20ay³) (x²+6x+9)/(x²-9) (m³-2m²-m)/(m²-m) (a²+ab)/(a²

约分 （6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²)（6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²) (16b²y²)/(20ay³) (x²+6x+9)/(x²-9) (m³-2m²-m)/(m²-m) (a²+ab)/(a²
约分 （6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²)
（6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²) (16b²y²)/(20ay³) (x²+6x+9)/(x²-9) (m³-2m²-m)/(m²-m) (a²+ab)/(a²-b²) 约分

约分 （6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²)（6ab²)/(8b³) (x³-2x²y)/(x²y-2xy²) (16b²y²)/(20ay³) (x²+6x+9)/(x²-9) (m³-2m²-m)/(m²-m) (a²+ab)/(a²
（6ab²)/(8b³) =3a/4b
(x³-2x²y)/(x²y-2xy²) =x²(x-2y)/xy(x-2y)=x/y
(16b²y²)/(20ay³)=4b²/(5ay)
(x²+6x+9)/(x²-9) =(x+3)²/(x+3)(x-3)=(x+3)/(x-3)
(m³-2m²-m)/(m²-m)=m(m²-2m-1)/m(m-1)=(m²-2m-1)/(m-1)
(a²+ab)/(a²-b²) =a(a+b)/(a+b)(a-b)=a/(a-b)