1、去括号:a+(b-c)=__________,a-(b-c)=__________,-(a-b)-c=__________.
2、化简:(x-1)-(1-x)=__________,x-2(x-1)=__________.
3、若A=a2-2ab,B=-3ab+b2,则3A-2B=__________.
4、若
,则2x2-5x+(x2+4x)-(3x2+2)的值为__________.
5、已知:a+b<0,
,则|a|+|a+b|+|ab|=__________.
6、若4x-3y=6,3x+2y=10,则14x-2y的值为__________.