\(\frac{x-2}{2017}+\frac{x-3}{2018}=\frac{x-4}{2019}+\frac{x-5}{2020}\)

<=> \(\frac{x-2}{2017}+1+\frac{x-3}{2018}+1=\frac{x-4}{2019}+1+\frac{x-5}{2020}+1\)

<=> \(\frac{x+2015}{2017}+\frac{x+2015}{2018}-\frac{x+2015}{2019}-\frac{x+2015}{2020}=0\)

<=> \(\left(x+2015\right)\left(\frac{1}{2017}+\frac{1}{2018}-\frac{1}{2019}-\frac{1}{2020}\right)=0\)

<=> x + 2015 = 0  ( vì \(\frac{1}{2017}+\frac{1}{2018}-\frac{1}{2019}-\frac{1}{2020}\ne0\)) 

<=> x = - 2015 

Vậy x = -2015.

Giải phương trình :

\(\frac{x-2}{2017}+\frac{x-3}{2018}=\frac{x-4}{2019}+\frac{x-5}{2020}\)

\(\Rightarrow\frac{x-2}{2017}+1+\frac{x-3}{2018}+1=\frac{x-4}{2019}+1+\frac{x-5}{2020}+1\)

\(\Rightarrow\frac{x+2015}{2017}+\frac{x+2015}{2018}-\frac{x+2015}{2019}-\frac{x+2015}{2020}=0\)

\(\Rightarrow\left(x+2015\right)\left(\frac{1}{2017}+\frac{1}{2018}-\frac{1}{2019}-\frac{1}{2020}\right)=0\)

Mà \(\left(\frac{1}{2017}+\frac{1}{2018}-\frac{1}{2019}-\frac{1}{2020}\right)>0\)

\(\Rightarrow x+2015=0\)

\(\Rightarrow x=-2015\)

\(\frac{x-2}{2017}+\frac{x-3}{2018}=\frac{x-4}{2019}+\frac{x-5}{2020}\)

\(\Rightarrow\left(\frac{x-2}{2017}+1\right)+\left(\frac{x-3}{2018}+1\right)=\left(\frac{x-4}{2019}+1\right)+\left(\frac{x-5}{2020}+1\right)\)

\(\Rightarrow\frac{x-2+2017}{2017}+\frac{x-3+2018}{2018}=\frac{x-4+2019}{2019}+\frac{x-5+2020}{2020}\)

\(\Rightarrow\frac{x+2015}{2017}+\frac{x+2015}{2018}=\frac{x+2015}{2019}+\frac{x+2015}{2020}\)

\(\Rightarrow\frac{x+2015}{2017}+\frac{x+2015}{2018}-\frac{x+2015}{2019}-\frac{x+2015}{2020}=0\)

\(\Rightarrow\left(x+15\right)\left(\frac{1}{2017}+\frac{1}{2018}-\frac{1}{2019}-\frac{1}{2020}\right)=0\)

\(\Rightarrow x+2015=0\)

\(\Rightarrow x=-2015\)

Vậy x = - 2015 

1 ( frac ) 2

\(\frac{2-x}{2016}-1=\frac{1-x}{2017}+\frac{x}{2018}\)

\(\Rightarrow\frac{2-x}{2016}-1=\frac{1-2018x}{4070306}+\frac{2017x}{4070306}\)

\(\Rightarrow\frac{2-x}{2016}-1=\frac{1-2018x+2017x}{4070306}\)

\(\Rightarrow\frac{2-x}{2016}-1=\frac{1-x}{4070306}\)

\(\Rightarrow\frac{2-x}{2016}-1+1=\frac{1-x}{4070306}+1\)

\(\Rightarrow\frac{2-x}{2016}=\frac{1-x+4070306}{4070306}\)

\(\Rightarrow\frac{2-x}{2016}=\frac{4070307-x}{4070306}\)

\(\Rightarrow4070306.\left(2-x\right)=2016.\left(4070307-x\right)\)

\(\Rightarrow8140612-4070306x=8205738912-2016x\)

\(\Rightarrow-4070306x+2016x=8205738912-8140612\)

\(\Rightarrow-4068290x=8197598300\)

\(\Rightarrow x=4,95\)

Vậy x=4,95

Chúc bn học tốt

Tham khảo :

Nhận thấy vế trái luôn dương nên \(x-2020\ge0\Leftrightarrow x\ge2020\)

Với \(x\ge2020\Rightarrow\left\{{}\begin{matrix}x-2017\ge0\\2x-2018\ge0\\3x-2019\ge0\end{matrix}\right.\)

PT trở thành: \(x-2017+2x-2018+3x-2019=x-2020\)

Hay kết hợp với điều kiện \(x=\dfrac{4034}{5}\) suy ra PT đã cho vô nghiệm 

\(\left|x-2017\right|+\left|2x-2018\right|+\left|3x-2019\right|=x-2020\)

\(ĐK:x\ge2020\)

\(\Leftrightarrow x-2017+2x-2018+3x-2019=x-2020\)

\(\Leftrightarrow5x=4034\)

\(\Leftrightarrow x=806,8\left(tm\right)\)

Vậy \(S=\left\{806,8\right\}\)

Ai giúp mình với! Cần gấp!

Ta co:

\(\left|x-2016\right|+\left|x-2018\right|=\left|x-2016\right|+\left|2018-x\right|\ge\left|x-2016+2018-x\right|=2\)

\(\left|x-2017\right|\ge0\)

\(\Rightarrow\left|x-2016\right|+\left|x-2017\right|+\left|x-2018\right|\ge2\)

Dau "=" xay ra tai \(\hept{\begin{cases}2016\le x\le2018\\x=2017\end{cases}}\)

Vay x=2017

đây có phải cách cấp 2 k bn??

Lời giải:

a.

PT $\Leftrightarrow (x+3)^2=2016^{2020}-17^{91}+9$

Ta thấy: $2016^{2020}-17^{91}+9\equiv 0-(-1)^{91}+0\equiv -1\equiv 2\pmod 3$

Mà 1 scp thì chia $3$ chỉ dư $0$ hoặc $1$ nên pt vô nghiệm.

b.

$x^2=2016(y-1)^2-2017^{2019}\equiv 0-1^{2019}\equiv 3\pmod 4$
Mà 1 scp chia $4$ chỉ dư $0$ hoặc $1$ nên vô lý.

Vậy pt vô nghiệm.

c.

$(x-1)^2=2017^{2017}+1\equiv 1^{2017}+1\equiv 2\pmod 4$
Mà 1 scp khi chia cho $4$ chỉ dư $0$ hoặc $1$ nên vô lý

Vậy pt vô nghiệm

d.

$(x+2)^2=2018^{10}+4\equiv (-1)^{10}+1\equiv 2\pmod 3$

Mà 1 scp khi chia $3$ dư $0$ hoặc $1$ nên vô lý

Vậy pt vô nghiệm.