Question

整式的加减之去括号1.(a-b)+(-c-d)=2.(a-b)-(-c-d)=3.-2(a-b)+(-c+d)=4.2(

Answer 1

1.(a-b)+(-c-d)= a-b-c-d

2.(a-b)-(-c-d)=a-b+c+d

3.-2(a-b)+(-c+d)=-2a+2b-c+d

4.2(a-b)-(-c+d)=2a-2b+c-d