解:(1)原式=8x2+14xy+12xy+21y2
=8x2+26xy+21y2;
(2)原式=9a2﹣4b2;
(3)原式=9x2﹣12x+4;
(4)原式=﹣3﹣1+4=0.
8角大于84分
My father was reading a book ________ I was doing my homework.
剧场能坐870人.一张票8元,如果一场票都卖完了,这场的票房收入是多少元?
____×____=____(元)