tìm x:
\(\frac{x-2}{12}=\frac{3}{x-2}\)
mn cho mik cách giải ạ
Càm ơn nhìu ạ
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\(\frac{x+2}{2019}+\frac{x+3}{2018}=\frac{x+4}{2017}+\frac{x}{2021}\)
\(\Leftrightarrow\frac{x+2}{2019}+1+\frac{x+3}{2018}+1=\frac{x+4}{2017}+1+\frac{x}{2021}+1\)
\(\Leftrightarrow\frac{x+2021}{2019}+\frac{x+2021}{2018}=\frac{x+2021}{2017}+\frac{x+2021}{2021}\)
\(\Leftrightarrow x+2021=0\)
\(\Leftrightarrow x=-2021\)
37-3x = 81
37-3x = 34
7 - 3x = 4
3x = 7 - 4
3x = 3
x = 3 : 3
x = 1
\(\frac{x-2016}{100}+\frac{x-2014}{102}+\frac{x-2016}{104}+...+\frac{x-2}{2114}=1008\)
\(\Rightarrow\frac{x-2016}{100}-1+\frac{x-2014}{102}-1+...+\frac{x-2}{2114}-1=0\)
\(\Rightarrow\frac{x-2116}{100}+\frac{x-2116}{102}+...+\frac{x-2116}{2114}=0\)
\(\Rightarrow\left(x-2116\right)\left(\frac{1}{100}+\frac{1}{102}+...+\frac{1}{2114}\right)=0\)
mà \(\frac{1}{100}+\frac{1}{102}+...+\frac{1}{2114}\ne0\)
\(\Rightarrow x-2116=0\)
\(\Rightarrow x=2116\)
P/s màu mè ghê ha =))
\(\frac{x-2016}{100}+\frac{x-2014}{102}+...+\frac{x-2}{2114}=1008\)
\(=>\frac{x-2016}{100}+\frac{x-2014}{102}+...+\frac{x-2}{2114}-1008=0\)
\(=>\frac{x-2016}{100}-1+\frac{x-2014}{102}-1+...+\frac{x-2}{2114}-1=0\)
\(=>\frac{x-2116}{100}+\frac{x-2116}{102}+...+\frac{x-2116}{2114}=0\)
\(=>\left(x-2116\right).\left(\frac{1}{100}+\frac{1}{102}+...+\frac{1}{2114}\right)=0\)
Do \(\frac{1}{100}+\frac{1}{102}+...+\frac{1}{2114}\ne0\)
\(=>x-2116=0\)
\(=>x=2116\)
Ta có: \(\frac{xy}{x+y}=\frac{yz}{y+z}=\frac{zx}{z+x}\)\(\Rightarrow\frac{xyz}{z\left(x+y\right)}=\frac{xyz}{x\left(y+z\right)}=\frac{xyz}{y\left(z+x\right)}\)\(\Rightarrow z\left(x+y\right)=x\left(y+z\right)=y\left(z+x\right)\)\(\Rightarrow zx+zy=xy+xz=yz+xy\)
Ta có: zx + zy = xy + xz => zy = xy => z = x (1)
Ta có: x - z = x - x = 0
\(a,\frac{x+2}{6}-\frac{8x+1}{3}=\frac{2-5x}{2}-6\)
\(\Leftrightarrow\frac{x+2}{6}-\frac{\left(8x+1\right)2}{6}=\frac{\left(2-5x\right)3}{6}-\frac{36}{6}\)
=> x + 2 - 16x - 2 = 6 - 15x - 36
<=> x - 16x + 15x = 6 -36 + 2 - 2
<=> 0x = -30
Phương trình vô ngiệm
b, 11 - ( x + 2) = 3(x + 1)
<=> 11 - x - 2= 3x + 3
<=> -x - 3x = 3 - 11 + 2
<=> -4x = -6
<=> x = \(\frac{3}{2}\)
C, tương tự a
c) ĐKXĐ: x \(\ne\)0 và x \(\ne\)-1
Ta có: \(\frac{x+3}{x+1}+\frac{x+2}{x}=2\)
=> \(x\left(x+3\right)+\left(x+1\right)\left(x+2\right)=2x\left(x+1\right)\)
<=> x2 + 3x + x2 + 3x + 2 = 2x2 + 2x
<=> 2x2 + 6x + 2 - 2x2 - 2x = 0
<=> 4x + 2 = 0
<=> 4x = -2
<=> x = -1/2 (tm)
Vậy S = {-1/2}
a.\(ĐKXĐ:\hept{\begin{cases}x^2-2x\ne0\\x-2\ne0\\x\left(x+1\right)\ne0\end{cases}\Leftrightarrow\hept{\begin{cases}x\left(x-2\right)\ne0\\x-2\ne0\\x\left(x+1\right)\ne0\end{cases}\Leftrightarrow}\hept{\begin{cases}x\ne0\\x\ne2\\x\ne-1\end{cases}}}\)
b.\(M=\left(\frac{1}{x^2-2x}+\frac{2}{x-2}\right)\div\frac{2x+1}{x\left(x+1\right)}\)
\(=\left(\frac{1}{x\left(x-2\right)}+\frac{2}{x-2}\right)\div\frac{2x+1}{x\left(x+1\right)}\)
\(=\left(\frac{1}{x\left(x-2\right)}+\frac{2x}{x\left(x-2\right)}\right)\div\frac{2x+1}{x\left(x+1\right)}\)
\(=\frac{2x+1}{x\left(x-2\right)}\div\frac{2x+1}{x\left(x+1\right)}\)
\(=\frac{2x+1}{x\left(x-2\right)}.\frac{x\left(x+1\right)}{2x+1}=\frac{x\left(2x+1\right)\left(x+1\right)}{x\left(x-2\right)\left(2x+1\right)}=\frac{x+1}{x-2}\)
c.Để \(M>1\)thì
\(\frac{x+1}{x-2}>1\)
c, Ta có : \(M>1\Rightarrow\frac{x+1}{x-2}>1\Leftrightarrow\frac{x+1}{x-2}-1>0\)
\(\Leftrightarrow\frac{x+1-x+2}{x-2}>0\Leftrightarrow\frac{3}{x-2}>0\)
\(\Rightarrow x-2>0\Leftrightarrow x>2\)vì 3 > 0
d, Để M nguyên khi \(x+1⋮x-2\Leftrightarrow x-2+3⋮x-2\)ĐK : \(x\ne2\)
\(\Leftrightarrow3⋮x-2\Rightarrow x-2\inƯ\left(3\right)=\left\{\pm1;\pm3\right\}\)
x - 2 | 1 | -1 | 3 | -3 |
x | 3 | 1 | 5 | -1 |
a, \(\frac{1}{1\cdot2\cdot3}+\frac{1}{2\cdot3\cdot4}+...+\frac{1}{x\cdot\left(x+1\right)\cdot\left(x+2\right)}=\frac{2018}{2019}\)
\(=\frac{1}{1\cdot2}-\frac{1}{2\cdot3}+\frac{1}{2\cdot3}-\frac{1}{3\cdot3}+...+\frac{1}{x\cdot\left(x+1\right)}-\frac{1}{\left(x+1\right)\cdot\left(x+2\right)}=\frac{2018}{2019}\)
\(=1-\frac{1}{\left(x+1\right)\cdot\left(x+2\right)}=\frac{2018}{2019}\)
\(\Rightarrow\frac{1}{\left(x+1\right)\cdot\left(x+2\right)}=1-\frac{2018}{2019}\)
\(\Rightarrow\frac{1}{\left(x+1\right)\cdot\left(x+2\right)}=\frac{2019}{2019}-\frac{2018}{2019}=\frac{1}{2019}\)
Đến đây bn tự tính nhé !!
Áp dụng tính chất tỉ lệ thức, ta có:
(x-2)(x-2) = 12.3
Suy ra (x-2)(x-2) = 36 = 62 = (-6)2
Suy ra hoặc x - 2 = 6 hoặc x -2 = - 6
Vậy x thuộc tập hợp gồm các phần tử là 8 hoặc -4
mk ko ghi lại đề nha
(x-12).(x-12)=3.12
x^2-24x+144=36
x^2-24x=-108
x(x-24)=-108
TH1 x=-108
TH2 x=-84
MK ko bít có đúng k
k mk nha=3