17/20, 16/3, 23/63, 17/2, 5/14

17/20, 16/3, 23/63, -17/2, 5/14

a; \(\frac35+\frac{14}{7}+\frac{4}{10}\)

= \(\frac35\) + 2 + \(\frac25\)

= (\(\frac35\) + \(\frac25\)) + 2

= 1+ 2

= 3

b; \(\frac27+\frac37+\frac47+\frac57+\frac67\)

= \(\frac57+\frac47+\frac57+\frac67\)

= \(\frac97+\frac57+\frac67\)

= \(\frac{14}{7}+\frac67\)

= \(\frac{20}{7}\)

5m2 2dm2=..............cm2

+)    = \(\frac{20}{7}\)

+)    = \(\frac{101}{22}\)

tk mik nha

mik khỏi chép lại đề

+) = \(\frac{7}{2}+\frac{33}{7}-\frac{75}{14}\)

= \(\frac{49}{14}+\frac{66}{14}-\frac{75}{14}\)

= \(\frac{115}{14}-\frac{75}{14}\)

= \(\frac{20}{7}\)

+) = \(\frac{9}{2}+\frac{1}{2}:\frac{11}{2}\)

= \(\frac{9}{2}+\frac{1}{2}\)x \(\frac{2}{11}\)

= \(\frac{9}{2}+\frac{1}{11}\)

= \(\frac{99}{22}+\frac{2}{22}\)

= \(\frac{101}{22}\)

tk nha b

A,\(\frac{7}{13}+\frac{1}{7}+\frac{18}{30}=\frac{49}{91}+\frac{13}{91}+\frac{18}{30}=\frac{62}{91}+\frac{18}{30}=\frac{1860}{2730}+\frac{1638}{2730}=\frac{583}{455}\)

B,\(\left(\frac{20}{21}+\frac{3}{14}\right)-\frac{2}{3}=\left(\frac{280}{294}+\frac{63}{294}\right)-\frac{2}{3}=\frac{7}{6}-\frac{2}{3}=\frac{21}{18}-\frac{12}{18}=\frac{9}{18}=\frac{1}{2}\)

C,\(=\frac{17}{5}+\frac{31}{7}=\frac{119}{35}+\frac{155}{35}=\frac{234}{35}\)

a) x−5/7-13/14 =1                                                                                                         

   x                 =5/7+13/14

    x                 =23/14

=>1=14/14

    x                  =14/14+23/14

    x                  =37/14

  b) 3/5 +x+1 1/5 =11/3 

   Chuyển 1 1/5=6/5

              x=11/3-6/5-3/5

              x=28/15  

\(3\frac{1}{2}=\frac{7}{2};4\frac{5}{7}=\frac{33}{7}\)

\(3\frac{1}{2}+4\frac{5}{7}-\frac{5}{14}\)

\(=\frac{7}{2}+\frac{33}{7}-\frac{5}{14}\)

\(=\frac{49}{14}+\frac{66}{14}-\frac{5}{14}\)

\(=\frac{115}{14}-\frac{5}{14}\)

\(=\frac{110}{14}=\frac{55}{7}\)