简算数学题

每个括号直接加减就可以了：
原式＝52/51×50/51×53/52×51/52×54/53×52/53×...×153/152×151/152
＝50/51×153/152
＝75/76

原式=[1-1/(51*51)]*[1-1/(52*52)]*[1-1/(53*53)]*............*[1-1/(152*152)] =[(51*51-1)/(51*51)]*[(52*52-1)/(52*52)]*[(53*53-1/(53*53)]*............*[(152*152-1)/(152*152)] =[(50*52)/(51*51)]*[(51*53)/(52*52)]*[(52*54/(53*53)]*............*[(151*153)/(152*152)] =50/51*153/152 =75/76