3a＋(-8a＋2)-(3-4a)
=(3-8+4)a+(2-3)
=-a-1
1∕4(-4x＋2x-8)-1/2(x-1)
=1/4(-2x-8)-1/2(x-1)
=-1/2*x-2-1/2*x+1/2
=-x-3/2
合并同类项：3a＋(-8a＋2)-(3-4a)
3a＋(-8a＋2)-(3-4a)
=(3-8+4)a+(2-3)
=-a-1
1∕4(-4x＋2x-8)-1/2(x-1)
=1/4(-2x-8)-1/2(x-1)
=-1/2*x-2-1/2*x+1/2
=-x-3/2