31995 - 81 / 42660 - 108 

= 31914 / 42552 

= 3.10638 / 4.10638 

= 3/4

=3/4

tk mk nha 

A = \(\frac{3^4\left(5.79-1\right)}{2^2.3^2\left(5.79-1\right)}=\frac{9}{4}\); B = \(\frac{3.7.13.37\left(5.11-1\right)}{4.3.7.13.37\left(3.5-1\right)}=\frac{54}{4.14}=\frac{2.9}{4.2.7}=\frac{9}{28}\)

Ta có:

\(\begin{array}{l}\frac{{24}}{{108}} = \frac{{24:12}}{{108:12}} = \frac{2}{9};\\\frac{{80}}{{32}} = \frac{{80:16}}{{32:16}} = \frac{5}{2}\end{array}\)

A = \(\frac{3469-54}{6938-108}\)

= \(\frac{3469-54}{2\left(3469-54\right)}\)

= \(\frac{1}{2}\)

B = \(\frac{2468-98}{3702-147}\)

= \(\frac{2\left(1234-49\right)}{3\left(1234-49\right)}\)

= \(\frac{2}{3}\)

BCNN(2,3) = 6

\(\frac{1}{2}=\frac{1.3}{2.3}=\frac{3}{6}\)

\(\frac{2}{3}=\frac{2.2}{3.2}=\frac{4}{6}\)

\(A=\frac{3469-54}{6938-108}=\frac{3469-54}{3469.2-54.2}=\frac{3469-54}{2.\left(3469-54\right)}=\frac{1}{2}=\frac{1.3}{2.3}=\frac{3}{6}\)

\(B=\frac{2468-98}{3702-147}=\frac{1234.2-49.2}{1234.3-49.3}=\frac{2.\left(1234-49\right)}{3.\left(1234-49\right)}=\frac{2}{3}=\frac{2.2}{3.2}=\frac{4}{6}\)

Dấu '/' đọc là phần nha! <3

A= 3469 - 54 / 6938 -108 = 3469 -54 / 2*(1234 -49) = 1/2

B= 2468 - 98 / 3702 - 147 = 2*(1234-49) / 3*(1234-49) =2/3

Sau khi rút gọn p/s ta đc: 1/2 và 2/3 => MC=6

Rồi quy đồng nha bạn 

KQ: 3/6 và 4/6

Không còn bạn nhé

Ai k tui tui k lại cho

\(A=\frac{4157-19}{12471-57}\)\(=\frac{4138}{12414}\)\(=\frac{4138:4138}{12414:4138}\)\(=\frac{1}{3}\)

\(B=\frac{7}{10^2+8.10^2}\)\(=\frac{7}{100+8.100}\)\(=\frac{7}{100+800}\)\(=\frac{7}{900}\)

\(C=\frac{31995}{42660-108}\)\(=\frac{31995}{42552}\)\(=\frac{31995:27}{42552:27}\)\(=\frac{1185}{1576}\)

\(D=\frac{2^{45}.5^3.2^6.3}{8.2^{18}.81.5}=\frac{2^{51}.5^3.3}{2^3.2^{18}.3^4.5}=\frac{2^{51}.5^3.3}{2^{21}.3^4.5}=\frac{2^{30}.5^2}{3^3}\)

k mình nhé.

A=4138/12414=1/3

B=7/900

C=31995/42552=1185/1576

Phần D tui chịu, ahihi