原式=1/4*(5-1)/1*5+1/4*(9-5)/5*9+.+1/4*(101-97)/101*97
=1/4[(1-1/5)+(1/5-1/9)+...+(1/97-1/101)]
=1/4[1-(1/5-1/5)-(1/9-1/9)-...-(1/97-1/97)-1/101)]
=1/4(1-1/101)
=25/101
如果有疑问请点【评论】或者【追问】简算：999*222+333*334原式=333*3*222+333*334 =333*（3*222）+333*334=333*（666+334） =333*1000 =333000