\(\frac{17}{23}.\frac{8}{6}.\frac{23}{17}.\left(-80\right).\frac{3}{4}\)

\(=\left(\frac{17}{23}.\frac{23}{17}\right).\left(\frac{8}{6}.\frac{3}{4}\right).\left(-80\right)\)

\(=1.1.\left(-80\right)\)

\(=-80\)

\(\frac{17}{23}\times\frac{8}{6}\times\frac{23}{17}\times\left(-80\right)\times\frac{3}{4}\)

\(=\left(\frac{17}{23}\times\frac{23}{17}\right)\times\left(\frac{8}{6}\times\frac{3}{4}\right)\times\left(-80\right)\)

\(=1\times1\times\left(-80\right)\)

\(=-80\)

a) \(\frac{17}{23}.\frac{18}{16}.\frac{23}{17}-\left(-80\right)-\frac{3}{4}\)

= \(\frac{17.18.23}{23.16.17}+80-\frac{3}{4}\)

= \(\frac{9}{8}+80-\frac{3}{4}\)

= \(\frac{3}{8}+80=\frac{643}{8}\)

b) \(\frac{5}{11}.\frac{18}{29}-\frac{5}{11}.\frac{8}{29}+\frac{5}{11}.\frac{19}{29}\)

= \(\frac{5}{11}.\left(\frac{18}{29}-\frac{8}{29}+\frac{19}{29}\right)\)

= \(\frac{5}{11}.1=\frac{5}{11}\)

c) \(\left(\frac{13}{23}+\frac{1313}{2323}-\frac{131313}{232323}\right).\left(\frac{1}{3}+\frac{1}{4}-\frac{7}{12}\right)\)

= \(\left(\frac{13}{23}+\frac{1313}{2323}-\frac{131313}{232323}\right).0\)

= \(0\)

\(=\dfrac{17}{23}\cdot\dfrac{23}{17}\cdot\dfrac{1}{2}\cdot\dfrac{3}{4}\cdot\left(-80\right)=-80\cdot\dfrac{3}{8}=-30\)

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?

3 ×17 + 3 × 25 - 3 × 2 = 3 × (17 + 25 – 2) = 3 × 40 = 120

Bài 1:

a; \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{7}{21}\) + (- \(\dfrac{10}{36}\) + \(\dfrac{11}{19}\)  + \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)

=  \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{1}{3}\) -\(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\) - \(\dfrac{5}{8}\)

= (\(\dfrac{5}{18}\) - \(\dfrac{10}{36}\)) + (\(\dfrac{8}{19}\) + \(\dfrac{11}{19}\)) - (\(\dfrac{1}{3}\) - \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)

= (\(\dfrac{5}{18}\) - \(\dfrac{5}{18}\)) + \(\dfrac{19}{19}\) - 0 - \(\dfrac{5}{8}\)

= 0 + 1 - \(\dfrac{5}{8}\)

= \(\dfrac{3}{8}\)

b; \(\dfrac{1}{13}\) + (\(\dfrac{-5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\)) - (\(\dfrac{12}{17}\) - \(\dfrac{5}{18}\) + \(\dfrac{7}{5}\))

= \(\dfrac{1}{13}\) - \(\dfrac{5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{12}{17}\) + \(\dfrac{5}{18}\) - \(\dfrac{7}{5}\)

= (\(\dfrac{1}{13}\) - \(\dfrac{1}{13}\)) + (\(\dfrac{12}{17}\) - \(\dfrac{12}{17}\)) + (-\(\dfrac{5}{18}\) + \(\dfrac{5}{18}\)) - \(\dfrac{7}{5}\)

= 0 + 0 + 0 - \(\dfrac{7}{5}\)

= - \(\dfrac{7}{5}\)

Bài 1 c;

   \(\dfrac{15}{14}\) - (\(\dfrac{17}{23}\) - \(\dfrac{80}{87}\) + \(\dfrac{5}{4}\)) + (\(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\))

=  \(\dfrac{15}{14}\) - \(\dfrac{17}{23}\) + \(\dfrac{80}{87}\) - \(\dfrac{5}{4}\) + \(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\)

= (\(\dfrac{15}{14}-\dfrac{15}{14}\)) + (\(-\dfrac{17}{23}+\dfrac{17}{23}\)) - (\(\dfrac{5}{4}\) - \(\dfrac{1}{4}\)) + \(\dfrac{80}{87}\)

= 0 + 0 - 1 + \(\dfrac{80}{87}\)

= - \(\dfrac{7}{87}\)

Bài 1 d; 

   \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) + (-\(\dfrac{23}{27}\) + \(\dfrac{-1}{25}\) - \(\dfrac{5}{43}\)) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)

= \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) - \(\dfrac{23}{27}\) - \(\dfrac{1}{25}\) - \(\dfrac{5}{43}\) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)

= (\(\dfrac{1}{25}\) - \(\dfrac{1}{25}\)) - (\(\dfrac{4}{27}\) + \(\dfrac{23}{27}\)) - (\(\dfrac{5}{43}\) - \(\dfrac{5}{43}\)) - \(\dfrac{4}{7}\)

= 0 - 1 - 0 - \(\dfrac{4}{7}\)

= \(\dfrac{-11}{7}\)