Ôn tập: Phương trình bâc nhất một ẩn

TT

Giải phương trình:

\(\dfrac{x-3}{2014}\)+\(\dfrac{x-2}{2015}\)=\(\dfrac{x-1}{1008}\)+\(\dfrac{x}{2017}\)-1

ND
9 tháng 3 2018 lúc 21:04

\(\dfrac{x-3}{2014}+\dfrac{x-2}{2015}=\dfrac{x-1}{1008}+\dfrac{x}{2017}-1\)

\(\Leftrightarrow\dfrac{x-3}{2014}-1+\dfrac{x-2}{2015}-1=\dfrac{x-1}{1008}-2+\dfrac{x}{2017}-1\) \(\Leftrightarrow\dfrac{x-3-2014}{2014}+\dfrac{x-2-2015}{2015}=\dfrac{x-1-2016}{1008}-\dfrac{x-2017}{2017}\) \(\Leftrightarrow\dfrac{x-2017}{2014}+\dfrac{x-2017}{2015}=\dfrac{x-2017}{1008}+\dfrac{x-2017}{2017}\)

\(\Leftrightarrow\left(x-2017\right)\left(\dfrac{1}{2014}+\dfrac{1}{2015}-\dfrac{1}{1008}-\dfrac{1}{2017}\right)=0\)

Vì: \(\dfrac{1}{2014}+\dfrac{1}{2015}-\dfrac{1}{1008}-\dfrac{1}{2017}\ne0\)

Suy ra: x -2017 = 0

=> x = 2017

Bình luận (0)
KK
9 tháng 3 2018 lúc 21:05

\(\dfrac{x-3}{2014}+\dfrac{x-2}{2015}=\dfrac{x-1}{1008}+\dfrac{x}{2017}-1\)

\(\dfrac{x-3}{2014}-1+\dfrac{x-2}{2015}-1=\dfrac{x-1}{2008}-2+\dfrac{x}{2017}-1\)

\(\dfrac{x-2017}{2014}+\dfrac{x-2017}{2015}=\dfrac{x-2017}{2008}+\dfrac{x-2017}{2017}\)

\(\dfrac{x-2017}{2014}+\dfrac{x-2017}{2015}-\dfrac{x-2017}{2008}-\dfrac{x-2017}{2017}=0\)

\(\left(x-2017\right)\left(\dfrac{1}{2014}+\dfrac{1}{2015}-\dfrac{1}{2008}-\dfrac{1}{2017}\right)=0\)

⇔x-2017=0

⇔x=2017

vậy phương trình có tập nghiệm là S={2017}

Bình luận (35)
KN
9 tháng 3 2018 lúc 21:08

\(\dfrac{x-3}{2014}+\dfrac{x-2}{2015}=\dfrac{x-1}{1008}+\dfrac{x}{2017}-1\)

\(\Leftrightarrow\) \(\dfrac{x-3}{2014}-1+\dfrac{x-2}{2015}-1=\dfrac{x-1}{1008}-2+\dfrac{x}{2017}-1\)

\(\Leftrightarrow\) \(\dfrac{x-3}{2014}-\dfrac{2014}{2014}+\dfrac{x-2}{2015}-\dfrac{2015}{2015}=\dfrac{x-1}{1008}-\dfrac{2016}{1008}+\dfrac{x}{2017}-\dfrac{2017}{2017}\)

\(\Leftrightarrow\)\(\dfrac{x-3-2014}{2014}+\dfrac{x-2-2015}{2015}=\dfrac{x-1-2016}{1008}+\dfrac{x-2017}{2017}\)

\(\Leftrightarrow\)\(\dfrac{x-2017}{2014}+\dfrac{x-2017}{2015}=\dfrac{x-2017}{1008}+\dfrac{x-2017}{2017}\)

\(\Leftrightarrow\) \(\dfrac{x-2017}{2014}+\dfrac{x-2017}{2015}-\dfrac{x-2017}{1008}-\dfrac{x-2017}{2017}=0\)

\(\Leftrightarrow\) \(\left(x-2017\right)\left(\dfrac{1}{2014}+\dfrac{1}{2015}-\dfrac{1}{1008}-\dfrac{1}{2017}\right)=0\)

\(\Leftrightarrow\) x - 2017 = 0

\(\Leftrightarrow\) x = 2017

Vậy.............

Bình luận (3)

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