Ta có: \(\frac{x+1}{2014}+\frac{x+2}{2013}+\frac{x+3}{2012}=\frac{x+4}{2011}+\frac{x+5}{2010}+\frac{x+6}{2009}\)

\(\Rightarrow\frac{x+1}{2014}+1+\frac{x+2}{2013}+1+\frac{x+3}{2012}+1=\frac{x+4}{2011}+1+\frac{x+5}{2010}+1+\frac{x+6}{2009}+1\)

\(\Rightarrow\frac{2015+x}{2014}+\frac{2015+x}{2013}+\frac{2015+x}{2012}=\frac{2015+x}{2011}+\frac{2015+x}{2010}+\frac{2015+x}{2009}\)

\(\Rightarrow\left(2015+x\right)\left(\frac{1}{2014}+\frac{1}{2013}+\frac{1}{2012}-\frac{1}{2011}-\frac{1}{2010}-\frac{1}{2009}\right)=0\)

=> 2015 + x = 0

=> x = -2015

Các bạn check lại ở dáp án của Ngọc Vĩ nhé!

Bài 1 : 

a, 5/7 - 3/6 + 2/7 + 9/6 - 4/3 - 1/3 

= (5/7 + 2/7) + (9/6 - 3/6) - (4/3 + 1/3)

= 1 + 1 - 5/3

= 2- 5/3

= 1/3

b. 0,75 + 5,64 + ( 7,25 - 3,14 )

= (0,75 + 7,25) + (5,64 - 3,14)

= 8 + 2,5

= 10,5

c, 15/26 x 39/25 x 54/18 x 36/27 ( Làm = cách triệt tiêu )

\(=\frac{15\cdot39\cdot54\cdot36}{26\cdot25\cdot18\cdot27}\)

\(=\frac{3\cdot5\cdot3\cdot13\cdot27\cdot2\cdot2\cdot18}{2\cdot13\cdot5\cdot5\cdot18\cdot27}\)

 
\(=\frac{3\cdot3\cdot2}{5}\)

\(=\frac{18}{5}\)
Bài 2 : Tìm x 

a, ( 6,73 + 5,26 - 3,5 ) - x = 4,32 - 2,56 

8,49 - x = 1,76

x= 8,49 - 1,76

x= 6,73

b, x : (  7,25 - 5,42 ) = 4,63 +1,37 

x : 1,83 = 6

x= 6 * 1,83 

x= 10,98

1) duoc ket qua la 32 con 

2) được 9 câu

3) bai 3 khong biet lam

ai giúp mình mình sẽ cảm ơn người đó

bạn ơi phải ghi bài giải phép tính đáp số đó

\(\frac{3}{4}\)-\(\frac{-5}{9}\)-\(\frac{11}{36}\)=\(\frac{27}{36}\)-\(\frac{-20}{36}\)-\(\frac{11}{36}\)=1

\(\frac{1}{9}\)+\(\frac{-5}{3}\)-\(\frac{-13}{18}\)=\(\frac{2}{18}\)+\(\frac{-30}{18}\)-\(\frac{-13}{18}\)=\(\frac{-15}{18}\)=\(\frac{-5}{6}\)

\(\frac{3}{4}-\frac{-5}{9}-\frac{11}{36}=\frac{27}{36}-\frac{-20}{36}-\frac{11}{36}=\frac{47}{36}-\frac{11}{36}=\frac{36}{36}=1\)

\(\frac{1}{9}+\frac{-5}{3}-\frac{13}{18}=\frac{2}{18}+\frac{-30}{18}-\frac{13}{18}=\frac{-28}{18}+\frac{13}{18}=\frac{-15}{18}=\frac{-5}{6}\)

đơn giản 

nhưng trả lời câu hỏi của tớ đã

\(\Leftrightarrow2\left(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{x\left(x+1\right)}\right)=\frac{2008}{2010}\)
\(\Leftrightarrow2\left(\frac{3-2}{2.3}+\frac{4-3}{3.4}+\frac{5-4}{4.5}+...+\frac{\left(x+1\right)-x}{x\left(x+1\right)}\right)=\frac{2008}{2010}\)
\(\Leftrightarrow2\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{x}-\frac{1}{x+1}\right)=\frac{2008}{2010}\)
\(\Leftrightarrow\frac{1}{2}-\frac{1}{x+1}=\frac{1004}{2010}\)
\(\Leftrightarrow\frac{1}{x+1}=\frac{1}{2010}\)
\(\Leftrightarrow x+1=2010\)
\(\Leftrightarrow x=2009\)