a: \(\dfrac{31995-81}{42660-108}=\dfrac{31914}{42552}=\dfrac{3}{4}\)

b: \(\dfrac{3\cdot5\cdot7\cdot11\cdot13\cdot37-10101}{1212120+40404}=\dfrac{545454}{1252524}=\dfrac{27}{62}\)

a, $\frac{31995-81}{42660-108}$

= $\frac{395.81-81}{395.108-108}$

=$\frac{81.394}{394.108}$

= $\frac{81}{108}$          = $\frac{3}{4}$

b, $\frac{3.5.7.11.13.37-10101}{1212120+40404}$

= $\frac{3.5.7.11.13.37-3.7.13.37}{\mathrm{3.7.12.13.37.10}+\mathrm{3.4.7.13.37}}$

= $\frac{\left(\mathrm{3.7.13.37}\right)(5.11-1)}{\left(\mathrm{3.7.13.37}\right)(120+4)}$

= $\frac{5.11-1}{120+4}$

= $\frac{54}{124}$ = $\frac{27}{62}$

A= [5.11.10101 -10101]/[10101.120+10101.4] = 10101.[5.11-1] / 101.[120+4] = 54/124=27/62

đúng nhé

\(=\frac{5.11.3.7.11.13-3.7.11.13}{120.10101+4.10101}=\frac{3.7.11.13\left(5.11-1\right)}{10101\left(120+4\right)}=\frac{10101.54}{10101.124}=\frac{54}{124}=\frac{27}{62}\)

\(\frac{27}{62}\)

\(\frac{27}{62}\)

\(a,A=\dfrac{201220122012}{201320132013}=\dfrac{201220122012:100010001}{201320132013:100010001}=\dfrac{2012}{2013}\)

\(b,B=\dfrac{3.5.7.11.13.37-10101}{1212120+40404}=\dfrac{5.11.10101-10101}{10101.120+10101.4}=\dfrac{10101.\left(5.11-1\right)}{10101.\left(120+4\right)}=\dfrac{54}{124}=\dfrac{27}{62}\)

Ta có:

\(A=\frac{3.5.7.11.13.37-10101}{1212120+40404}\)

\(=\frac{\left(3.7.11.13.37\right).5-10101.1}{120.10101+4.10101}\)

\(=\frac{10101.\left(5-1\right)}{10101.\left(120+4\right)}\)

\(=\frac{4}{124}=\frac{1}{31}\)

Sai rồi:

A = 5.11.(3.7.13.37) - 10101/(10101.120 + 10101.4)

= (5.11.10101 - 10101)/(10101.120+10101.4)

= 10101(5.11-1)/10101(120+4)

= 27/62.

A= 5.11.(3.7.13.37)-10101/(10101.120+10101.4)

=(5.11.10101-10101)/(10101.120+10101.4)

=10101.(5.11-1)/10101(120+4)

=27/62

k mik nha mik k lại 100 cái lun

.5.7.11.13.37-10101/1212120+40404

=3.5.7.11.13.37-10101/1212120.1/10+40404 (vì 1/1212120=1/121212.1/10)

= 3.37.7.11.13.5-101010/121212.1/100+40404

=111.1001.5-5/6.1/100+40404

=151515.5-250/3

=595959-250/3

=1787876/3

1787876/3

A=3.5.7.11.13.37-10101/1212120+40404

A=(5.11).(3.7.13.37)-10101/10101.120+4.10101

A=55.10101-10101/10101.(120+4)

A=10101.(55-1)/10101.124

A=54/124

A=27/62