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x-1009/1001+x-4/1003+x+2010/1005=7
((x-1009/1001)-1))+((x-4/1003)-2)+((x+2010/1005)-4))=0
(x-2010/1001)+(x-2010/1003)+(x-2010/1005)=0
(x-2010)*(1/1001+1/1003+1/1005)=0
okk!!!!!!!!!!!!!!!
\(\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}=7\)
\(\Leftrightarrow\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}-7=0\)
\(\Leftrightarrow\left(\dfrac{x-1009}{1001}-1\right)+\left(\dfrac{x-4}{1003}-2\right)+\left(\dfrac{x+2010}{1005}-4\right)=0\)
\(\Leftrightarrow\dfrac{x-2010}{1001}+\dfrac{x-2010}{1003}+\dfrac{x-2010}{1005}=0\)
\(\Leftrightarrow\left(x-2010\right)\left(\dfrac{1}{1001}+\dfrac{1}{1003}+\dfrac{1}{1005}\right)=0\)
\(\Leftrightarrow x-2010=0\)
\(\Rightarrow x=2010\)
Vậy....
\(\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}=7\)
\(\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}-7=0\)
\(\left(\dfrac{x-1009}{1001}-1\right)+\left(\dfrac{x-4}{1003}-2\right)+\left(\dfrac{x+2010}{1005}-4\right)=0\)
\(\dfrac{x-2010}{1001}+\dfrac{x-2010}{1003}+\dfrac{x-2010}{1005}=0\)
\(\left(x-2010\right)\left(\dfrac{1}{1001}+\dfrac{1}{1003}+\dfrac{1}{1005}\right)=0\)
\(x-2010=0\)
\(x=2010\)
Vậy x = 2010
ta có :
\(\frac{x-1009}{1001}-1+\frac{x-4}{1003}-2+\frac{x+2010}{1005}-4=0\)
hay \(\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\Leftrightarrow x-2010=0\)
hay x =2010
Vậy phương trình có nghiệm x = 2010
\(\frac{x-1003}{1007}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\Rightarrow\left(\frac{x-1003}{1007}-1\right)+\left(\frac{x-4}{1003}-1\right)+(\frac{x+2010}{1005}-4)=0\)
\(\Rightarrow\frac{x-2010}{1007}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
\(\Rightarrow\left(x-2010\right)\left(\frac{1}{1007}+\frac{1}{1003}+\frac{1}{1005}\right)\)
Vì
\(\frac{1}{1007}+\frac{1}{1003}+\frac{1}{1005}\ne0\Rightarrow X-2010=0\Rightarrow x=2010\)
\(\frac{x-1003}{1007}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\frac{x-1003}{1007}-1+\frac{x-4}{1003}-2+\frac{x+2010}{1005}-4=0\)
\(\frac{x-2010}{1003}+\frac{x-2010}{1005}+\frac{x-2010}{1007}=0\)
\(\left(x-2010\right)\left(\frac{1}{1003}+\frac{1}{1005}+\frac{1}{1007}\right)=0\)
\(\frac{1}{1003}+\frac{1}{1005}+\frac{1}{1007}\ne0\)
\(\Rightarrow x-2010=0\Rightarrow x=2010\)
\(\frac{x-1009}{1001}\)+\(\frac{x-4}{1003}\)+\(\frac{x+2010}{1005}\)=7
⇔\(\frac{x-1009}{1001}\)+\(\frac{x-4}{1003}\)+\(\frac{x+2010}{1005}\)-7=0
⇔\(\left(\frac{x-1009}{1001}-1\right)+\left(\frac{x-4}{1003}-2\right)+\left(\frac{x+2010}{1005}-4\right)=0\)
⇔\(\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
⇔(x-2010)\(\left(\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}\right)\)=0
⇔x-2010=0
⇔x=2010
Vậy x=2010
\(\frac{x-1009}{1001}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
⇔ \(\frac{x-1009}{1001}+\frac{x-4}{1003}+\frac{x+2010}{1005}-7=0\)
⇔\(\left(\frac{x-1009}{1001}-1\right)+\left(\frac{x-4}{1003}-2\right)\)\(+\left(\frac{x+2010}{1005}-4\right)=0\)
⇔\(\frac{x-1009-1001}{1001}+\frac{x-4-2006}{1003}+\)\(\frac{x+2010-4020}{1005}=0\)
⇔\(\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
⇔\(\left(x-2010\right)\left(\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}\right)=0\)
⇔ \(x-2010=0\left(do\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}>0\right)\)
⇔ \(x=2010\)
Vậy S = {2010}
Lời giải:
Tập xác định của phương trình
Sử dụng tính chất tỉ lệ thức, có thể biến đổi phương trình như sau
Lời giải thu được
\(\frac{x+2012}{2}+\frac{x+2010}{3}+\frac{x+2011}{5}=\frac{x}{1008}+\frac{x-2}{1009}+\frac{x+1}{2015}\)
\(\Leftrightarrow\frac{x+2012}{2}+\frac{x+2010}{3}+\frac{x+2011}{5}-\frac{x}{1008}-\frac{x-2}{1009}-\frac{x+1}{2015}=0\)
\(\Leftrightarrow\frac{x+2012}{2}+2+\frac{x+2010}{3}+2+\frac{x+2011}{5}+1-\frac{x}{1008}-2-\frac{x-2}{1009}-2-\frac{x+1}{2015}-1=0\)
\(\Leftrightarrow\frac{x+2016}{2}+\frac{x+2016}{3}+\frac{x+2016}{5}-\frac{x+2016}{1008}-\frac{x+2016}{1009}-\frac{x+2016}{2015}=0\)
\(\Leftrightarrow\left(x+2016\right)\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{5}-\frac{1}{1008}-\frac{1}{1009}-\frac{1}{2015}\right)=0\)
Mà \(\frac{1}{2}+\frac{1}{3}+\frac{1}{5}-\frac{1}{1008}-\frac{1}{1009}-\frac{1}{2015}\ne0\)
\(\Leftrightarrow x+2016=0\)
\(\Leftrightarrow x=-2016\)
Vậy tập nghiệm của phương trình là \(S=\left\{-2016\right\}\)
\(\Leftrightarrow\frac{x-1009}{1001}-1+\frac{x-4}{1003}-2+\frac{x+2010}{1005}-4=0\)
\(\Leftrightarrow\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
\(\Leftrightarrow\left(x-2010\right)\left(\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}\right)=0\)
\(\Leftrightarrow x=2010\)
\(\frac{x-1009}{1001}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\Leftrightarrow\frac{x-1009}{1001}-1+\frac{x-4}{1003}-2+\frac{x+2010}{1005}-4=0\)
\(\Leftrightarrow\frac{x-1009-1001}{1001}+\frac{x-4-2006}{1003}+\frac{x+2010-4020}{1005}=0\)
\(\Leftrightarrow\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
\(\Leftrightarrow\left(x-2010\right)\left(\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}\right)=0\)
\(\Leftrightarrow x-2010=0\)
\(\Leftrightarrow x=2010\)
V...\(S=\left\{2010\right\}\)
^^
\(\frac{x-1009}{1001}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\Leftrightarrow\left(\frac{x-1009}{1001}-1\right)+\left(\frac{x-4}{1003}-2\right)+\left(\frac{x+2010}{1005}-4\right)=0\)
\(\Leftrightarrow\frac{x-1009-1001}{1001}+\frac{x-4-2006}{1003}+\frac{x+2010-4020}{1005}=0\)
\(\Leftrightarrow\frac{x-2010}{1001}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
\(\Leftrightarrow\left(x-2010\right)\left(\frac{1}{1001}+\frac{1}{1003}+\frac{1}{1005}\right)=0\)
\(\Leftrightarrow x-2010=0\)
\(\Leftrightarrow x=2010\)
a.giá trị nhỏ nhất hả bạn?
ta có: B = x4-x2+2x+7
=x4-2x2+1+x2+2x+1+5
=(x2-1)2+(x+1)2+5\(\ge5\)
vậy min B=5
dấu "=" xảy ra \(\Leftrightarrow x=-1\)
b.\(\frac{x+6}{1005}+2+\frac{x+132}{471}+4\frac{x+1008}{168}+6=0\)
\(\Leftrightarrow\frac{x+2016}{1005}+\frac{x+2016}{471}+\frac{x+2016}{168}=0\)
\(\Leftrightarrow\left(x+2016\right)\left(\frac{1}{1005}+\frac{1}{471}+\frac{1}{168}\right)=0\)
dễ thấy x+2016=0 =>x=-2016
vậy...