1.去括号
(1)-（2m-3)
=-2m+3
(2)n-3（4-2m）
= n-12+6m
(3)16a-8（3b+4c）
= 16a-24b-32c
(4)4t+2/3(12-9v)
=4t+8-6v
(5)-(5m+n)-7(a-3b)
=-5m-n-7a+21b
(6)-1/2(x+y)+1/4(p+q)
= -1/2x-1/2y+1/4p+1/4q
(7)-8(3a-2ab+4)
=-24a+16ab-32)
(8)4(m+p)-7(n-2q)
=4m+4p-7n+14q
2.化简下列各式
(1)-2n-(3n-1)
=-2n-3n+1
=-5n+1
(2)a-(5a-3b)+(2b-a)
=a-5a+3b+2b-a
=-5a+5b
(3)-3(2s-5)+6s
=-36s+15+6s
=-30s+15
(4)1-(2a-1)-(3a+3)
= 1-2a+1-3a-3
=-5a-1
(5)3(-ab_a)-(3a-b)
=-3ab_3a-3a+b
=-3ab-6a+b
(6)14(abc-2a)+3(6a-abc)
=14abc-28a+18a-3abc
=11abc-10a
(7)3(xy-2z)+(-xy+3z)
=3xy-6z-xy+3z
=2xy-3z
(8)-4(pq+pr)+(4pq+pr)
=-4pq-4pr+4pq+pr
=-3p