(1)a-(5a-3b)+(2b-a)
=a-5a+3b+2b-a
=5a+5b
(2)14(abc-2a)+3(6a-2abc)
=14abc-28a+18a-6abc
=8abc-10a
(3)-4(pq+pr)+(4pq+pr)
=-4pq-4pr+4pq+4pr
=0
(1)a-(5a-3b)+(2b-a)
=a-5a+3b+2b-a
=5a+5b
(2)14(abc-2a)+3(6a-2abc)
=14abc-28a+18a-6abc
=8abc-10a
(3)-4(pq+pr)+(4pq+pr)
=-4pq-4pr+4pq+4pr
=0