【導(dǎo)讀】C.單項(xiàng)式乘以多項(xiàng)式,積的項(xiàng)數(shù)與多項(xiàng)式項(xiàng)數(shù)相同;D.多項(xiàng)式乘以多項(xiàng)式,合并同類項(xiàng)前,積的項(xiàng)數(shù)等于兩個(gè)多項(xiàng)式的項(xiàng)數(shù)之和.A.(a-2)(a+3);B.(a+2)(a-3);C.(a-6)(a+1);D.(a+6)(a-1).-x=x2-x;D.(x+1)(x-3)=x2+x-3.A.m,n同時(shí)為負(fù);B.m,n同時(shí)為正;C.m,n異號(hào);D.m,n異號(hào)且絕對(duì)值小的為正.2)3(成立,且M是一個(gè)多項(xiàng)式,N是一個(gè)整數(shù),則()。觀察你所得到的結(jié)果,你發(fā)現(xiàn)了什么規(guī)律?并根據(jù)你的結(jié)論填空:(x-1)