Question

几道初二题 帮帮忙····急！！！！！！！！

1）a+1分之a×a²分之a²-1=
2）a分之3+5a分之a-15=
3)m²-4分之4+2-m分之1=
要过程，快·谢谢

Answer 1

[a/(a+1)]×[(a^2-1)/a^2]
=[a/(a+1)]×[(a+1)×(a-1)/a^2]
=(a-1)/a
1-1/a

3/a+(a-15)/5a
=3/a+1/5-3/a
=1/5

4/(m^2-4)+1/(2-m)
=4/[(m-2)(m+2)]-1/(m-2)
=[4-(m+2)]/[(m-2)(m+2)]
=(2-m)/[(m-2)(m+2)]
=-1/(m+2)