6/13:1/(2+y) =15/39

<=> (12+6y)/13=15/39

<=> 468+234y=195

<=>234y=-273

<=> y=-7/6

6/13+ -14/39=

nhớ ghi rõ cách làm ( tính nhanh )

Ta có : \(\frac{3}{5}+\frac{6}{11}+\frac{7}{13}+\frac{2}{5}+\frac{5}{11}+\frac{19}{13}+\frac{1}{2}+\frac{2}{3}-\frac{1}{6}\)

\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{6}{11}+\frac{5}{11}\right)+\left(\frac{7}{13}+\frac{19}{13}\right)+\left(\frac{1}{2}+\frac{2}{3}-\frac{1}{6}\right)\)

\(=1+1+2+1=5\)

\(\frac{3}{5}+\frac{6}{11}+\frac{7}{13}+\frac{2}{5}+\frac{5}{11}+\frac{19}{13}:\frac{1}{2}+\frac{2}{3}-\frac{1}{6}\)

\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{19}{13}-\frac{7}{13}\right)+\left(\frac{6}{11}+\frac{5}{11}\right):\frac{2}{3}+\frac{1}{6}\)

\(=1+1+1:\frac{2}{3}+\frac{1}{6}\)

\(=3:\frac{2}{3}+\frac{1}{6}\)

\(=\frac{9}{2}+\frac{1}{6}\)

\(=\frac{14}{3}\)

= (3/5 + 2/5) + (6/11 + 5/11) + (7/13 + 19/13) : 1/2 + 2/3 - 1/6

= (1 + 1 + 2) : (1/2 + 4/6 - 1/6)

= 4 : (1/2 + 1/2)

= 4 : 1

= 4

Vậy kết quả bằng 4

giúp mk với

mong ban ghi han hoi :)

khó đọc quá

hỏi google phay

Hỏi gg đi khó lắm

Xin lỗi  vì ko giúp cho bạn vì khó lắm

theo mình đoán là:

y = 60 

chúc bạn học tốt !!!

y + y x 1/3 : 2/9 + y : 2/7 = 360

=> y + y x 1/3 x 9/2 + y x 7/2 = 360

=> y + y x 3/2 + y x 7/2 = 360

=> y x ( 1 + 3/2 + 7/2 ) = 360

=> y x  6 = 360

=> y = 360 : 6

=> y = 60

Vậy y = 60

Chúc bạn học tốt !!! 

\(y+y\times\frac{1}{3}:\frac{2}{9}+y:\frac{2}{7}=360\)

\(y+y\times\frac{1}{3}\times\frac{9}{2}+y\times\frac{7}{2}=360\)

\(y+y\times\frac{3}{2}+y\times\frac{7}{2}=360\)

\(y\times\left(1+\frac{3}{2}+\frac{7}{2}\right)=360\)

\(y\times6=360\)

\(y=360:6\)

\(y=60\)

x + 7/12 = 11/6 : 2/1 

x + 7/12 = 11/12 

        x     = 11/12 - 7/12

        x     = 1/3 

a) \(\frac{3}{2}-\frac{5}{6}:x=\frac{5}{15}-\frac{3}{15}\)

\(\Leftrightarrow\frac{3}{2}-\frac{5}{6}:x=\frac{2}{15}\)

\(\Leftrightarrow\frac{5}{6}:x=\frac{3}{2}-\frac{2}{15}\)

\(\Leftrightarrow\frac{5}{6}:x=\frac{41}{30}\)

\(\Leftrightarrow x=\frac{5}{6}:\frac{41}{30}\)

\(\Leftrightarrow x=\frac{25}{41}\)

b) \(x-\frac{6}{7}.\frac{14}{8}=\frac{1}{2}-\frac{2}{5}\)

\(\Leftrightarrow x-\frac{3}{2}=\frac{1}{10}\)

\(\Leftrightarrow x=\frac{1}{10}+\frac{3}{2}\)

\(\Leftrightarrow x=\frac{8}{5}\)

c) \(x:\frac{6}{5}+\frac{2}{3}=\frac{7}{3}\)

\(\Leftrightarrow x:\frac{6}{5}=\frac{7}{3}-\frac{2}{3}\)

\(\Leftrightarrow x:\frac{6}{5}=\frac{5}{3}\)

\(\Leftrightarrow x=\frac{5}{3}.\frac{6}{5}\)

\(\Leftrightarrow x=2\)

huyền ngốc

\(\trac{3}{2}

a=-31 phần 60

b=13 phần 4

c=-2

em mới có lớp 2