ai nhanh tui cho hay nhất Question ai nhanh tui cho hay nhất in progress 0 Môn Toán Thu Thủy 4 years 2021-05-12T22:56:23+00:00 2021-05-12T22:56:23+00:00 1 Answers 7 views 0
Answers ( )
Đáp án:
Giải thích các bước giải:
A = 1/1.2+1/2.3/1+3.6+…….+1/99.100
= 1-1/2+1/2-1/3+1/3-1/6+………1/99-1/100
= 1-1/100
= 99/100
Vậy A = 99/100
B = 1/1.3+1/3.5+1/5.7+……..+1/99.101
= 1-1/3+1/3-1/5+1/5-1/7+……….+1/99-1/100
= 1-1/101
= 100/101
Vậy B = 100/101
C = 1-3/1.4-3/4.7-3/7.11-……..3/100.103
= 1-(1/1.4+1/4/7+1/7.11+……+1/100.103).1.1/3
= 1-( 1-1/4+1/4-1/7+1/7-1/11+…….+1/100-1/103).1/3
= 1-(1-1/103).1/3
= 1-(102/103. 1/3)
= 1- 34/103
= 69/103
Vậy C = 69/103
D = 1-1/1.6-1/6.11-1/11.16-……-1/96.101
= 1-(1/1.6+1/6.11+1/11.16+…….+1/96.101)
= 1-(1-1/6+1/6-1/11+1/11-1/16+……..+1/96-1/101)
= 1-(1-1/101)
= 1- 100/101
= 1/101
Vậy D = 1/101
=