c/
C = 1/100-1/100-1/99-1/99-1/98-1/98-1/97-..........-1/3-1/2-1/2-1/1
C = 1/100-1/100-1/1
C = 0-1/1
C = -1

= (11+9+2)+(1/2-3/2+5/2)-(2/3+5/3-7/3)

=22+1,5-0

=23.5

=(11+9+2)+(1/2-3/2+5/2)-(2/3+5/3-7/3)

=22+1,5-0

=23.5

Chúc học tốt

\(\text{A = }\frac{\text{-1}}{\text{2011}}-\frac{\text{3}}{\text{11}^2}-\frac{\text{5}}{\text{11}^2.\text{11}}-\frac{\text{7}}{\text{11}^2.\text{11}^2}=\text{ }\frac{\text{-1}}{\text{2011}}-\frac{\text{1}}{\text{11}^2}.\left(3-\frac{\text{5}}{\text{11}}-\frac{\text{7}}{\text{11}^2}\right)\)

\(\text{B = }\frac{\text{-1}}{\text{2011}}-\frac{7}{\text{11}^2}-\frac{5}{\text{11}^2.\text{11}}-\frac{3}{\text{11}^2.\text{11}^2}=\frac{\text{-1}}{\text{2011}}-\frac{\text{1}}{\text{11}^2}.\left(7-\frac{5}{\text{11}}-\frac{3}{\text{11}^2}\right)\)

\(\text{Vì }3-\frac{\text{5}}{\text{11}}-\frac{\text{7}}{\text{11}^2}< 7-\frac{5}{\text{11}}-\frac{3}{\text{11}^2}\)

\(\Rightarrow\frac{\text{-1}}{\text{2011}}-\frac{\text{1}}{\text{11}^2}.\left(3-\frac{\text{5}}{\text{11}}-\frac{\text{7}}{\text{11}^2}\right)>\frac{\text{-1}}{\text{2011}}-\frac{\text{1}}{\text{11}^2}.\left(7-\frac{5}{\text{11}}-\frac{3}{\text{11}^2}\right)\)

=> A > B

Vậy A > B

Sửa đề: Tìm các giá trị nguyên X thỏa mãn

3: \(\frac{-5}{11}<\frac{9}{x}<\frac{-5}{12}\)

=>\(\frac{-45}{99}<\frac{-45}{-5x}<\frac{-45}{108}\)

=>\(\frac{45}{99}>\frac{45}{-5x}>\frac{45}{108}\)

=>99<-5x<108

=>\(-\frac{99}{5}>x>-\frac{108}{5}\)

mà x nguyên

nên x∈{-20;-21}

4: Ta có: \(\frac{-11}{13}<\frac{9}{x}<\frac{-11}{15}\)

=>\(\frac{-99}{117}<\frac{-99}{-11x}<\frac{-99}{135}\)

=>\(\frac{99}{117}>\frac{99}{-11x}>\frac{99}{135}\)

=>117<-11x<135

=>\(-\frac{117}{11}>x>-\frac{135}{11}\)

mà x nguyên

nên x∈{-11;-12}

5: Ta có: \(\frac{-4}{5}<\frac{9}{x}<\frac{-4}{7}\)

=>\(\frac{-36}{45}<\frac{-36}{-4x}<\frac{-36}{28}\)

=>\(\frac{36}{45}>\frac{36}{-4x}>\frac{36}{28}\)

=>45<-4x<28

=>\(-\frac{45}{4}>x>-\frac{28}{4}\)

mà x nguyên

nên x∈∅

Mn ơi cho mình hỏi tick kiểu gì ạ mình mới dùng web này nên ko biết 

Bài 1 :

  0,7 + 0,6 - \(\frac{3}{7}\)- \(\frac{3}{13}\)

=    1,3 - \(\frac{3}{7}\)- \(\frac{3}{13}\)

=       \(\frac{61}{70}\)- \(\frac{3}{13}\)

=             \(\frac{583}{910}\)

2,75 + 2,2 - \(\frac{11}{7}\)- \(\frac{11}{13}\)

=    4,95 - \(\frac{11}{7}-\frac{11}{13}\)

=        \(\frac{473}{140}-\frac{11}{13}\)

=                  \(\frac{4609}{1820}\)

=43/306:599/105x1473/1820

=1505/61098x1473/1820

=0.01993613035