沪科版七年级上册2.2整式加减同步练习题含答案
1. 下列运算正确的是( )
A.-2(3x-1)=-6x-1
B.-2(3x-1)=-6x+1
C.-2(3x-1)=6x-2
D.-2(3x-1)=-6x+2
2.-x+y-z的相反数是( )
A.x-y+z B.x-y+z
C.x+y-z D.x+y+z
3.下列去括号正确的是( )
A.a-(b+c+d)=a-b+c+d
B.m2-(m-2)=m2-m-2
C.a-2(b+c+1)=a-2b-c-1
D.-6(x2-2x-1)=-6x2+12x+6
4.化简-(3m-2n)+2(2m-3n)的结果正确的是( )
A.m-4n B.-m+n
C.-m+4n D.m-n
5.去掉下列各式的括号:
(1)(a-b)+(c-d)=___________________;
(2)(a+b)-(c-d)=___________________;
(3)(a+b)-(-c+d)=______________________;
(4)-[-a-(b-c)]=______________.