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\(\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}=7\)
\(\Leftrightarrow\dfrac{x-1009}{1001}+\dfrac{x-4}{1003}+\dfrac{x+2010}{1005}-7=0\)
\(\Leftrightarrow\left(\dfrac{x-1009}{1001}-1\right)+\left(\dfrac{x-4}{1003}-2\right)+\left(\dfrac{x+2010}{1005}-4\right)=0\)
\(\Leftrightarrow\dfrac{x-2010}{1001}+\dfrac{x-2010}{1003}+\dfrac{x-2010}{1005}=0\)
\(\Leftrightarrow\left(x-2010\right)\left(\dfrac{1}{1001}+\dfrac{1}{1003}+\dfrac{1}{1005}\right)=0\)
\(\Leftrightarrow x-2010=0\)
\(\Rightarrow x=2010\)
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
\(\frac{x-1003}{1007}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\Rightarrow\left(\frac{x-1003}{1007}-1\right)+\left(\frac{x-4}{1003}-1\right)+(\frac{x+2010}{1005}-4)=0\)
\(\Rightarrow\frac{x-2010}{1007}+\frac{x-2010}{1003}+\frac{x-2010}{1005}=0\)
\(\Rightarrow\left(x-2010\right)\left(\frac{1}{1007}+\frac{1}{1003}+\frac{1}{1005}\right)\)
Vì
\(\frac{1}{1007}+\frac{1}{1003}+\frac{1}{1005}\ne0\Rightarrow X-2010=0\Rightarrow x=2010\)
\(\frac{x-1003}{1007}+\frac{x-4}{1003}+\frac{x+2010}{1005}=7\)
\(\frac{x-1003}{1007}-1+\frac{x-4}{1003}-2+\frac{x+2010}{1005}-4=0\)
\(\frac{x-2010}{1003}+\frac{x-2010}{1005}+\frac{x-2010}{1007}=0\)
\(\left(x-2010\right)\left(\frac{1}{1003}+\frac{1}{1005}+\frac{1}{1007}\right)=0\)
\(\frac{1}{1003}+\frac{1}{1005}+\frac{1}{1007}\ne0\)
\(\Rightarrow x-2010=0\Rightarrow x=2010\)
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 \(S=\left\{-2016\right\}\)
a)Ta có
\(x^2+y^2=1\Rightarrow\left(x^2+y^2\right)^2=1\)
\(\Rightarrow\frac{x^4}{a}+\frac{y^4}{b}=\frac{\left(x^2+y^2\right)^2}{a+b}\)
\(\Rightarrow\frac{x^4b+y^4a}{ab}=\frac{x^4+y^4+2x^2y^2}{a+b}\)
\(\Rightarrow\left(x^4b+y^4a\right)\left(a+b\right)=\left(x^4+y^2-2x^2y^2\right)ab\)
\(\Rightarrow x^4ab+x^4b^2+y^4ab+y^4a^2=x^4ab+y^4ab+2x^2y^2ab\)
\(\Rightarrow x^4b^2+y^4b^2-2x^2y^2ab=0\)
\(\Rightarrow\left(x^2b-y^2a\right)^2=0\)
\(\Rightarrow x^2b-y^2a=0\)
\(\Rightarrow x^2b=y^2a\left(dpcm\right)\)
b) từ kết quả câu a) ta suy ra dc
\(\frac{x^2}{a}=\frac{y^2}{b}\)
\(\Rightarrow\frac{x^2}{a}=\frac{y^2}{b}=\frac{x^2+y^2}{a+b}\)
Mà \(x^2+y^2=1\)
\(\Rightarrow\frac{x^2}{a}=\frac{y^2}{b}=\frac{1}{a+b}\)
\(\Rightarrow\left(\frac{x^2}{a}\right)^{1005}=\left(\frac{y^2}{b}\right)^{1005}=\frac{1^{1005}}{\left(a+b\right)^{1005}}\Rightarrow\frac{x^{2010}}{a^{1005}}=\frac{y^{2010}}{b^{1005}}=\frac{1}{\left(a+b\right)^{1005}}\)
\(\Rightarrow\frac{x^{2010}}{a^{1005}}+\frac{y^{2010}}{b^{1005}}=\frac{1}{\left(a+b\right)^{1005}}+\frac{1}{\left(a+b\right)^{1005}}=\frac{2}{\left(a+b\right)^{1005}}\left(dpcm\right)\)
Vầy đúng không nhỉ nếu đúng T I C K cho mình nha
Ko biết có nhanh nhất ko nhưng dù sao cũng xong rồi
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...
\(\frac{x-1}{2009}+\frac{x-2}{2010}=\frac{x+5}{2003}+\frac{x+7}{2001}\)
\(\Leftrightarrow\frac{x-1}{2009}+1+\frac{x-2}{2010}+1=\frac{x+5}{2003}+1+\frac{x+7}{2001}+1\)
\(\Leftrightarrow\frac{x-1}{2009}+\frac{2009}{2009}+\frac{x-2}{2010}+\frac{2010}{2010}=\frac{x+5}{2003}+\frac{2003}{2003}+\frac{x+7}{2001}+\frac{2001}{2001}\)
\(\Leftrightarrow\frac{x+2008}{2009}+\frac{x+2008}{2010}=\frac{x+2008}{2003}+\frac{x+2008}{2001}\)
\(\Leftrightarrow\frac{x+2008}{2009}+\frac{x+2008}{2010}-\frac{x+2008}{2003}-\frac{x+2008}{2001}=0\)
\(\Leftrightarrow\left(x+2008\right)\left(\frac{1}{2009}+\frac{1}{2010}-\frac{1}{2003}-\frac{1}{2001}\right)=0\)
\(\Leftrightarrow x+2008=0\Leftrightarrow x=-2008\)
\(\frac{x+1}{2011}+\frac{x+2}{2010}=\frac{x+3}{2009}+\frac{x+4}{2008}\Leftrightarrow\frac{x+1}{2011}+1+\frac{x+2}{2010}+1=\frac{x+3}{2009}+1+\frac{x+4}{2008}+1\)
\(\Leftrightarrow\frac{x+1}{2011}+\frac{2011}{2011}+\frac{x+2}{2010}+\frac{2010}{2010}=\frac{x+3}{2009}+\frac{2009}{2009}+\frac{x+4}{2008}+\frac{2008}{2008}\)
\(\Leftrightarrow\frac{x+1+2011}{2011}+\frac{x+2+2010}{2010}=\frac{x+3+2009}{2009}+\frac{x+4+2008}{2008}\)
\(\Leftrightarrow\frac{x+2012}{2011}+\frac{x+2012}{2010}=\frac{x+2012}{2009}+\frac{x+2012}{2008}\)
\(\Leftrightarrow\left(x+2012\right)\left(\frac{1}{2011}+\frac{1}{2010}\right)=\left(x+2012\right)\left(\frac{1}{2009}+\frac{1}{2008}\right)\)
\(\Leftrightarrow\left(x+2012\right)\left(\frac{1}{2011}+\frac{1}{2010}-\frac{1}{2009}-\frac{1}{2008}=0\right)\)
mà 1/2011+1/2010-1/2009-1/2008 khác 0
\(\Rightarrow x+2012=0\Rightarrow x=-2012\)
\(\left(3x-2\right)^2-x\left(9x-2\right)=24\Leftrightarrow9x^2-12x+4-9x^2+2x=24\)
\(\Leftrightarrow-10x+4=24\Leftrightarrow-10x=20\Leftrightarrow x=-2\)
1; Ta có : x+1/2011 + x+2/2010 = x+3/2009 + x+4/ 2008
Suy ra: 2+(x+1/2011 + x+2/2010 ) = 2+( x+3/2009 + x+4/2008)
suy ra ban tach 2=1+1 roi cong 1 voi tưng phân số trên nha sẽ ra kết quả ngay thôi
2; gợi ý nè : (3x-2)^2 =(3x)^2 + 2*3x*2+2^2
Gợi ý :
Bài 1 : Cộng thêm 1 vào 3 phân thức đầu, trừ cho 3 ở phân thức thứ 4, có nhân tử chung là (x+2020)
Bài 2 : Trừ mỗi phân thức cho 1, chuyển vế và có nhân tử chung là (x-2021)
Bài 3 : Phân thức thứ nhất trừ đi 1, phân thức hai trù đi 2, phân thức ba trừ đi 3, phân thức bốn trừ cho 4, phân thức 5 trừ cho 5. Có nhân tử chung là (x-100)
bài 3
\(\frac{x-90}{10}+\frac{x-76}{12}+\frac{x-58}{14}+\frac{x-36}{16}+\frac{x-15}{17}=15.\)
=>\(\frac{x-90}{10}-1+\frac{x-76}{12}-2+\frac{x-58}{14}-3+\frac{x-36}{16}-4+\frac{x-15}{17}-5=0\)
=>\(\frac{x-100}{10}+\frac{x-100}{12}+\frac{x-100}{14}+\frac{x-100}{16}+\frac{x-100}{17}=0\)
=>\(\left(x-100\right).\left(\frac{1}{10}+\frac{1}{12}+\frac{1}{14}+\frac{1}{16}+\frac{1}{17}\right)=0\)
=>(x-100)=0 do \(\frac{1}{10}+\frac{1}{12}+\frac{1}{14}+\frac{1}{16}+\frac{1}{17}\ne0\)
=> x=100
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!!!!!!!!!!!!!!!
Thanks bingodeo nhé :))