(1/2 + 1/6 + 1/8 +1/16) : x = 1/2 +1/6 +1/12 +1/20 +... + 1/132

41/48:x=1/2 +1/6 +1/12 +1/20 +... + 1/132

41/48:x=1/1x2+1/2x3+1/3x4+......+1/11x12

41/48:x=1-1/2+1/2-1/3+1/3-1/4+.....+1/11-1/12

41/48:x=1-1/12

41/48:x=11/12

          x=41/48:11/12

          x=41/44

Đáp án:

Ta có :

Vế phải:

   `1/2 +1/6 +1/12 +1/20 +... + 1/132`

`= 1/1.2 + 1/2.3 + 1/3.4 + 1/4.5 + .. +1/11.12`

`= 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5 + ... + 1/11 - 1/12`

`= 1 - 1/12`

`= 11/12`

Vế trái:

`(1/2 + 1/6 + 1/8 +1/16) `

`= 41/48` 

Ta lại có :

`(1/2 + 1/6 + 1/8 +1/16) : x = 1/2 +1/6 +1/12 +1/20 +... + 1/132`

`41 / 48 : x = 11/12`

`x = 41/48 : 11/12 `

`x = 41/44`

Chúc bn học tốt !

Cho mình câu trả lời hay nhất nhé 

Mơn ^ω^

@Jimmykoduvn

#Knock Down AnyBody