Cho B = 1/3 +1/16 +1/19 +1/21 +1/61 +1/72 +1/83 +1/94. So sánh B
Giải thích
B=B=13+116+119+121+161+172+183+194 < 13+115+115+115+160+160+160+160 < 13+315+460=515+315+115=35⇒B < 35
B=B=13+116+119+121+161+172+183+194 < 13+115+115+115+160+160+160+160 < 13+315+460=515+315+115=35⇒B < 35