105/790=21/158

105/790=21/158

a; \(\dfrac{1919}{2121}\) = \(\dfrac{1919:101}{2121:101}\) = \(\dfrac{19}{21}\)

b; 17 x 5 - \(\dfrac{17}{120}\) - 103

= 85 - \(\dfrac{17}{120}\) - 103

= \(\dfrac{10200}{120}\) - \(\dfrac{17}{120}\) - \(\dfrac{12360}{120}\)

= \(\dfrac{10183}{120}\) - \(\dfrac{12360}{120}\)

= \(\dfrac{-2177}{120}\)

c; 2929 - \(\dfrac{101}{2\times1919}\) + 404

= 2929 - \(\dfrac{1}{38}\) + 404

= \(\dfrac{111302}{38}\) - \(\dfrac{1}{38}\) + \(\dfrac{15352}{38}\)

= \(\dfrac{111301}{38}\) + \(\dfrac{15352}{38}\)

 = \(\dfrac{126653}{38}\)

\(\frac{25}{100}=\frac{25:25}{100:25}=\frac{1}{4}\)

\(\frac{72}{54}=\frac{72:18}{54:18}=\frac{4}{3}\)

\(\frac{60}{80}=\frac{60:20}{80:20}=\frac{3}{4}\)

\(\frac{35}{210}=\frac{35:35}{210:35}=\frac{1}{6}\)

25/100=1/4

72/54=4/3

60/80=3/4

35/210=1/6

\(\dfrac{12\times1}{12\times6}=\dfrac{1}{6}\)

\(\dfrac{12}{72}=\dfrac{12:12}{72:12}=\dfrac{1}{6}\)

\(\frac{72}{84}\)= \(\frac{6}{7}\)

6/7 nha

tk mình nha

\(\frac{72}{84}=\frac{6}{7}\) nha 

HT

:)))

~~~~~~~~~~~~~~~~~~~~~~~~~~

=6/7 T.I.C.K MÌNH ĐI BẠN IU

\(24m=\frac{24}{1000}km=\frac{3}{125}km.\)

6 yến = \(\frac{6}{100}\)tấn = \(\frac{3}{50}\)tấn.

------------------------------------------------------------------------

\(\frac{1515}{1717}=\frac{1515\div101}{1717\div101}=\frac{15}{17}\)

24m = \(\frac{24}{1000}\)km = \(\frac{3}{125}\)km

6 yến = \(\frac{6}{100}\)tấn = \(\frac{3}{50}\)tấn

\(\frac{1515}{1717}\)= \(\frac{15}{17}\)

Rút gọn:

\(\frac{35}{45}=\frac{35}{45}:\frac{5}{5}=\frac{7}{9}\)

HT

35/45 = 35 : 5 / 45 : 5 = 7/9 nhé

143/132=1,083

3535/3737=0,945

ko dư nha