\(\frac{x+2015}{5}+\frac{x+2016}{4}=\frac{x+2017}{3}+\frac{x+2018}{2}\)

\(\Leftrightarrow\left(\frac{x+2015}{5}+1\right)+\left(\frac{x+2016}{4}+1\right)=\left(\frac{x+2017}{3}+1\right)+\left(\frac{x+2018}{2}+1\right)\)

\(\Leftrightarrow\frac{x+2020}{5}+\frac{x+2020}{4}-\frac{x+2020}{3}-\frac{x+2020}{2}=0\)

\(\Leftrightarrow\left(x+2020\right)\left(\frac{1}{5}+\frac{1}{4}-\frac{1}{3}-\frac{1}{2}\right)=0\)

\(\Leftrightarrow x+2020=0\)vì \(\frac{1}{5}+\frac{1}{4}+\frac{1}{3}+\frac{1}{2}\ne0\)

\(\Leftrightarrow x=-2020\)

khó lắm

bây h thì bạn giải đc chưa

Cảm ơn bạn rất nhiều mình đã hiểu rồi 

Chúc bạn học tốt nhé

a) \(\frac{-8}{x}=\frac{-x}{18}\)

=> x.(-x) = (-8).18

=> -x² = -144

=> x² = 144 => x = \(\pm12\)

b) \(\frac{2x+3}{6}=\frac{x-2}{5}\)

=> 5(2x + 3) = 6(x - 2)

=> 10x + 15 - 6x + 12 = 0

=> 4x + 27 = 0

=> 4x = -27

=> x = -27/4

c) \(\frac{x+1}{22}=\frac{6}{x}\)

=> x(x + 1) = 22.6 = 132

=> x(x + 1) = 11.12

=> x = 11

\(\frac{-8}{x}=\frac{-x}{18}\)

\(\Leftrightarrow-8\cdot18=x\cdot\left(-x\right)\)

\(\Leftrightarrow-144=-x^2\)

\(\Leftrightarrow144=x^2\)

\(\Leftrightarrow\left(\pm12\right)^2=x^2\)

\(\Leftrightarrow\pm12=x\)

\(\frac{2x+3}{6}=\frac{x-2}{5}\)

\(\Leftrightarrow\left(2x+3\right)\cdot5=6\left(x-2\right)\)

\(\Leftrightarrow10x+15=6x-12\)

\(\Leftrightarrow10x-6x=-12-15\)

\(\Leftrightarrow4x=-27\)

\(\Leftrightarrow x=-\frac{27}{4}\)

\(\frac{x+1}{22}=\frac{6}{x}\)

\(\Leftrightarrow\left(x+1\right)x=22\cdot6\)

\(\Leftrightarrow\left(x+1\right)x=132\)

\(\Leftrightarrow\left(x+1\right)x=12\cdot11\)

\(\Leftrightarrow x=11\)

a) ĐKXĐ : x khác 0

\(\frac{-8}{x}=\frac{-x}{18}\)

\(\Leftrightarrow-x^2=-144\)

\(\Leftrightarrow x^2=144\)

\(\Leftrightarrow\orbr{\begin{cases}x=12\\x=-12\end{cases}}\)

b) \(\frac{2x+3}{6}=\frac{x-2}{5}\)

\(\Leftrightarrow5\left(2x+2\right)=6\left(x-2\right)\)

\(\Leftrightarrow10x+10=6x-12\)

\(\Leftrightarrow10x-6x=-10-12\)

\(\Leftrightarrow4x=-22\Leftrightarrow x=\frac{-11}{2}\)

c) ĐKXĐ : x khác 0

 \(\frac{x+1}{22}=\frac{6}{x}\)

\(\Leftrightarrow x\left(x+1\right)=132\)

Lập bảng làm nốt :))

\(\frac{1}{2}\left(x+1\right):\frac{3}{7}=\frac{32}{135}\)

\(\frac{1}{2}\left(x+1\right)=\frac{32}{135}.\frac{3}{7}\)

\(\frac{1}{2}\left(x+1\right)=\frac{32}{315}\)

\(x+1=\frac{32}{315}:\frac{1}{2}\)

\(x+1=\frac{64}{315}\)

\(x=\frac{64}{315}-1=-\frac{251}{315}\)

Ap dung t/c day ti so bang nhau

ta co x+1/9=x+2/8=x+3/7=x+4/6=x+1-x-2-x-3+x+4 tat ca phan 9-8-7+6 =0

suy ra x+1/9=0 suy ra x-1+0 x+-1

a) \(-\frac{3}{4}x+\frac{1}{6}x=1-2\frac{5}{9}\)
    \(\left(-\frac{3}{4}+\frac{1}{6}\right).x=1-\frac{23}{9}\)
                     \(-\frac{7}{12}.x=-\frac{14}{9}\)
                                  \(x=-\frac{14}{9}:\left(-\frac{7}{12}\right)\)
                                  \(x=\frac{8}{3}\)
Vậy x = ...
b) \(\left|2x-\frac{3}{8}\right|+2\frac{3}{4}=3\frac{1}{16}\)
     \(\left|2x-\frac{3}{8}\right|+\frac{11}{4}=\frac{49}{16}\)
                    \(\left|2x-\frac{3}{8}\right|=\frac{49}{16}-\frac{11}{4}\)      
                    \(\left|2x-\frac{3}{8}\right|=\frac{5}{16}\)
 \(\Rightarrow\left|2x-\frac{3}{8}\right|\in\text{{}\frac{5}{16};-\frac{5}{16}\)}
Nếu, \(2x-\frac{3}{8}=\frac{5}{16}\)
                     \(2x=\frac{11}{16}\)
                        \(x=\frac{11}{32}\)
Nếu, \(2x-\frac{3}{8}=-\frac{5}{16}\)
                     \(2x=\frac{1}{16}\)
                        \(x=\frac{1}{32}\)
Vậy \(x\in\text{{}\frac{1}{32};\frac{11}{32}\)}
                     

\(\frac{7}{8}.(\frac{2}{12}+\frac{4}{10})\)

\(\Rightarrow\frac{7}{8}.(\frac{10+24}{60})\)

\(\Rightarrow\frac{7}{8}.\frac{34}{60}=\frac{238}{480}\)

bt2

\(2.x-\frac{5}{4}=\frac{20}{15}\)

\(\Leftrightarrow2x=\frac{20}{15}+\frac{5}{4}\)

\(\Leftrightarrow2x=\frac{80+75}{60}\)

\(\Leftrightarrow2x=2,5\)

\(\Leftrightarrow x=1,25\)

.7/8.(1/6+2/5)=7/8.17/30=119/240

3/2-5/6:1/4+\(\sqrt{4}\)=3/2-10/3+2=1/6

2x=20/15+5/4

2x=31/12

x=31/12:2

x=31/24

ko bt nha thông cảm

\(=\frac{74}{15}\)

x = 47/40

x = 74/15

x= 74/15 

**** cái koai thien ty tfboys