Giải thích các bước giải:

a, Ta có: `A = (1+3+5+...+2005)(135135.137-135.137137)`

Dễ thấy: `135135.137-135.137137= 135.1001.137-135.1001.137 = 0`

`-> A = (1+3+5+...+2005)(135135.137-135.137137) = 0`

b, Ta có: `B =(2+4+6+...+2006)(26.333-108.111)` 

Dễ thấy: `26.333-108.111 =36.3.111-36.3.111 = 0`

`-> B =(2+4+6+...+2006)(26.333-108.111) = 0`

c, Ta có: `C = {(1+2+...+512)(101.102-101.101-50-51)}/(2+4+8+...+1024)`

Dễ thấy: `101.102-101.101-50-51 = 101.(102-201)- 101 = 0`

`-> C = {(1+2+...+512)(101.102-101.101-50-51)}/(2+4+8+...+1024) =0`

d, Ta có: `D = (41.66+34.41)/(3+7+...+79)`

`-> D = {41.(66+34)}/{[(79+3)[(79-3):4+1]]/2}``=(41.100)/{(82.20)/2}``=41.100/820 = 5`

e, Ta có: `E = (1+2+3+...+200)/(6+8+...+34) = [[(200+1)200]/2]/{[(34 + 6)[(34-6):2+1]]/2} = 201.100/[(40.15)/2] = 67`

f, Ta có: `F = (1.5.6+2.10.12+4.20.24+9.45.54)/(1.3.5+2.6.10+4.12.20+9.27.45)=(1.5.2.3+2.6.2.10+4.2.12.20+9.2.27.45)/(1.3.5+2.6.10+4.12.20+9.27.45)=[2(1.3.5+2.6.10+4.12.20+9.27.45)]/(1.3.5+2.6.10+4.12.20+9.27.45)=2 `

xin lỗi vì trl hơi nhiều