A = `8/3.5` + `8/5.7` + …. + `8/101.103`

2 bình luận về “A = `8/3.5` + `8/5.7` + …. + `8/101.103`”

1. A=[8]/[3.5]+[8]/[5.7]+…+[8]/[101.103]

   =4.([2]/[3.5]+[2]/[5.7]+…+[2]/[101.103])

   =4.([1]/[3]-[1]/[5]+[1]/[5]-[1]/[7]+…+[1]/[101]-[1]/[103])

   =4.([1]/[3]-[1]/[103])

   =4.[100]/[309]

   =[4.100]/[309]

   =[400]/[309]

   Vậy A=[400]/[309]

   Trả lời
2. A = 8/(3.5) + 8/(5.7) + … 8/(101 . 103)

   A =8/2 . ( (5-3)/(3.5) + (7-5)/(5.7) + … + (103-101)/(101.103))

   A = 8/2 . (2/(3.5) + 2/(5.7) + … + 2/(101.103))

   A = 4 . ( 1/3 – 1/5 + 1/5 – 1/7 + …. + 1/101 – 1/103)

   A = 4 . [1/3 + (-1/5 + 1/5) + …… + (-1/101 + 1/101) – 1/103]

   A = 4.(1/3 – 1/103)

   A =4 . 100/309

   A =400/309 

    

   Trả lời