Сократите дроби
1)12n^2/24mn^2+42n
2)40cd^2-10d/25d^2
3)9n^2/9mn^2+6n

1.12n^2/2n(12mn+21)=6n/12mn+212.40cd^2-10d/25d^2=5d(8cd-2)/25d^2=8cd-2/5d3.9n^2/9mn^2+6n=9n^2/3n(3mn+2)=3n/3mn+2