1 the first article, "Village Residence" is accompanied by two ancient poems.

Teaching objectives

a 1+a2+¡­¡­a(n- 1)+an=n^2an

& gt& gta 1+a2+¡­¡­a(n- 1)=(n^2- 1)an

& gt& gt£¿ s(n- 1)=(n^2- 1)[sn-s(n- 1)]

& gt& gtsn/s(n- 1)=n^2/(n^2- 1)=n/(n+ 1)*n/(n- 1)

(1) 20 14 how to divide the college entrance examination subjects in ordinary high schools?