\(B=\frac{17}{10}+\frac{17}{40}+\frac{17}{188}+\frac{17}{154}+\frac{17}{238}\)

\(B=\frac{17}{2.5}+\frac{17}{8.5}+\frac{17}{11.8}+\frac{17}{11.14}+\frac{17}{14.17}\)

\(\frac{3}{17}B=\frac{3}{2.5}+\frac{3}{8.5}+\frac{3}{11.8}+\frac{3}{11.14}+\frac{3}{14.17}\)

\(\frac{3}{17}B=\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+...+\frac{1}{14}-\frac{1}{17}\)

\(\frac{3}{17}B=\frac{1}{2}-\frac{1}{17}=\frac{17}{34}-\frac{2}{34}=\frac{15}{34}\)

\(B=\frac{15}{34}:\frac{3}{17}=\frac{15}{34}.\frac{17}{3}=\frac{5}{2}\)

Học tốt!!!

17/(10+40+88+154+238)

17/530

17 x 513 - 17 - 17 x 10   

= 17 x (513 - 1 - 10)

= 17 x 502

= 8534

40 x 86 x 25

= 25 x 4 x 10 x 86

= 100 x 860

= 86000

26,72 + \(\frac{13}{100}\) + \(\frac{21}{40}\)

= 26,72 + 0,13 + 0,525

= 26,85 + 0,525

= 27,375

\(\frac{1}{4}+\frac{17}{50}+\frac{31}{100}\)

= 0,25 + 0,34 + 0,31

= 0,59 + 0,31

= 0,9

\(\frac{3}{4}+\frac{15}{40}+\frac{69}{300}\)

= 0,75 + 0,375 + 0,23

= 1,125 + 0,23

= 1,355

\(\frac{42}{700}+\frac{42}{120}+\frac{17}{80}\)

= 0,06 + 0,35 + 0,2125

= 0,41 + 0,2125

= 0,6225

cảm ơn bạn

mình có ý kiến?

= 5

5

\(=\left(\dfrac{1}{8}+\dfrac{2}{5}-\dfrac{3}{40}\right):\left[\dfrac{80}{7}+\dfrac{17}{2}\cdot\dfrac{-877}{84}\right]\)

\(=\dfrac{5+16-3}{40}\cdot\dfrac{168}{-4489}=\dfrac{9}{20}\cdot\dfrac{-168}{4489}=\dfrac{-378}{22445}\)