a) \(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+........+\frac{1}{99.100}\)

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+.........+\frac{1}{99}-\frac{1}{100}\)

\(=\frac{1}{2}-\frac{1}{100}=\frac{49}{100}\)

b) \(\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+..........+\frac{2}{73.75}\)

\(=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+.......+\frac{1}{73}-\frac{1}{75}\)

\(=\frac{1}{3}-\frac{1}{75}=\frac{8}{25}\)

c) \(\frac{4}{4.6}+\frac{4}{6.8}+\frac{4}{8.10}+..........+\frac{4}{64.66}\)

\(=2.\left(\frac{2}{4.6}+\frac{2}{6.8}+\frac{2}{8.10}+..........+\frac{2}{64.66}\right)\)

\(=2.\left(\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+\frac{1}{8}-\frac{1}{10}+.....+\frac{1}{64}-\frac{1}{66}\right)\)

\(=2.\left(\frac{1}{4}-\frac{1}{66}\right)=2.\frac{31}{132}=\frac{31}{66}\)

d) \(\frac{9}{5.8}+\frac{9}{8.11}+\frac{9}{11.14}+........+\frac{9}{497.500}\)

\(=3.\left(\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}+..........+\frac{3}{497.500}\right)\)

\(=3.\left(\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+......+\frac{1}{497}-\frac{1}{500}\right)\)

\(=3.\left(\frac{1}{5}-\frac{1}{500}\right)=3.\frac{99}{500}=\frac{297}{500}\)

e) \(\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+......+\frac{1}{93.95}\)

\(=\frac{1}{2}.\left(\frac{2}{5.7}+\frac{2}{7.9}+\frac{2}{9.11}+........+\frac{2}{93.95}\right)\)

\(=\frac{1}{2}.\left(\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+........+\frac{1}{93}-\frac{1}{95}\right)\)

\(=\frac{1}{2}.\left(\frac{1}{5}-\frac{1}{95}\right)=\frac{1}{2}.\frac{18}{95}=\frac{9}{95}\)

g) \(\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+..........+\frac{1}{200.203}\)

\(=\frac{1}{3}.\left(\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+........+\frac{3}{200.203}\right)\)

\(=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+......+\frac{1}{200}-\frac{1}{203}\right)\)

\(=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{203}\right)=\frac{1}{3}.\frac{201}{406}=\frac{67}{406}\)

bạn juventus ơi , bạn làm nốt cho mình mấy câu sau với 

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

1^3-3^5-(-3^5)+1^64-2^9-1^36+1^15

=1+(-3^5+3^5)+1-2^9-1+1

=2-2^9

=-510

bằng 45 nha  bn

k nha

chúc bn học giỏi

đáp án là 45 nha bn mk cx chẳng bít mk tính đúng hay sai nữa zì mk tính zội

cho kv zới

1 + 2 + 3 + 4 + 5 + 6 + 7 + 9 + 0 = 45

NHé k mình nha ^^!

(9+1)+(8+2)+(7+3)+(6+4)+10+5

=10+10+10+10+10+5=45

9+3+2+1+7+8+5+10+6+4= (9+1)+(2+8)+(3+7)+(4+6)+5=10+10+10+10+5=10.4+5=40+5=45

(9+1)+(3+7)+(2+8)+(6+4)+10

=10+10+10+10+10

=50

#)Trả lời :

a)   \(\frac{-1}{2}+\frac{2}{7}-\frac{5}{28}\)

    \(=\frac{-3}{14}-\frac{5}{28}\)

    \(=\frac{-11}{28}\)

b)  \(5\frac{3}{4}+\left(\frac{1}{9}-1\frac{3}{4}\right)\)

   \(=\left(5\frac{3}{4}-1\frac{3}{4}\right)+\frac{1}{9}\)

   \(=4+\frac{1}{9}\)

   \(=4\frac{1}{9}=\frac{37}{9}\)

c)  \(\frac{-5}{7}x\frac{2}{11}+\frac{-5}{7}x\frac{9}{11}+3\frac{5}{7}\)

   \(=\frac{-5}{7}x\left(\frac{2}{11}+\frac{9}{11}\right)+3\frac{5}{7}\)

   \(=\frac{-5}{7}x1+3\frac{5}{7}\)

   \(=\frac{-5}{7}+3\frac{5}{7}\)

   \(=\frac{-5}{7}+\frac{26}{7}\)

   \(=\frac{21}{7}=3\)

            #~Will~be~Pens~#

14,67896825 là kết quả đó

chúc các bạn học giỏi

bạn ơi tại sao bạn lại ra kết quả nh vậyke chi tiết hơn được không vậy

câu trả lời là 123 nha bạn

\(\frac{1}{5}-\frac{3}{7}+\frac{5}{9}-\frac{2}{11}+\frac{7}{13}-\frac{9}{16}-\frac{7}{13}+\frac{2}{11}-\frac{5}{9}+\frac{3}{7}-\frac{1}{5}\)

\(=\left(\frac{1}{5}-\frac{1}{5}\right)+\left(\frac{2}{11}-\frac{2}{11}\right)+\left(\frac{5}{9}-\frac{5}{9}\right)+\left(\frac{3}{7}-\frac{3}{7}\right)+\left(\frac{7}{13}-\frac{7}{13}\right)-\frac{9}{16}\)

\(=\frac{-9}{16}\)