Ta có: \(12\left(x+2\right)=12x\)

\(\Rightarrow12x+24=12x\)

\(\Rightarrow12x-12x=-24\)

\(\Rightarrow0=-24\)(vô lí)

Vậy không có x thỏa mãn

Ta có : 12( x + 2 ) =12x

=> 12x + 24 = 12x

=> 12x - 12x = -24

=> 0 = -24 ( vô lí )

Vậy x có thể = 0

\(\frac{12}{x}=\frac{12}{x+2}\)

=> 12 . ( x + 2 ) = 12x

=> 12x + 24 = 12x

=> 24 = 12x - 12x

=> 24 = ( 12 - 12 )x

=> 24 = 0x

=> x = 24 : 0

=> x không tìm được

\(\frac{x-1}{3}+\frac{x-1}{5}+\frac{x-1}{7}+....+\frac{x-1}{99}=0\)

\(\left(x-1\right).\left(\frac{1}{3}+\frac{1}{5}+\frac{1}{7}+.....+\frac{1}{99}\right)=0\)

Vì \(\left(\frac{1}{3}+\frac{1}{5}+\frac{1}{7}+.....+\frac{1}{99}\right)>0\)

\(\Rightarrow x-1=0\)

=> x = 1

\(\frac{2}{3}x+\frac{1}{2}x=\frac{15}{12}\)

\(x.\left(\frac{2}{3}+\frac{1}{2}\right)=\frac{5}{4}\)

\(x.\left(\frac{4}{6}+\frac{3}{6}\right)=\frac{5}{4}\)

\(x.\frac{7}{6}=\frac{5}{4}\)

\(x=\frac{5}{4}:\frac{7}{6}\)

\(x=\frac{30}{28}\)

\(x=\frac{15}{14}\)

đặt x ra ngoài,trong ngoặc có cái chi cái chi ó,rùi tính!

eh eh eh kb eh

kb eh!!!=)

a)\(-\frac{2}{5}+\frac{2}{3}x+\frac{1}{6}x=-\frac{4}{5}\Leftrightarrow\frac{5}{6}x=-\frac{2}{5}\Leftrightarrow x=-\frac{12}{25}\)
Vậy nghiệm là x = -12/25

b)\(\frac{3}{2}x-\frac{2}{5}-\frac{2}{3}x=-\frac{4}{15}\Leftrightarrow\frac{5}{6}x=\frac{2}{15}\Leftrightarrow x=\frac{4}{25}\)
Vậy nghiệm là x = 4/25

c)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)
\(\Leftrightarrow x+1=0\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\ne0\right)\)\(\Leftrightarrow x=-1\)
Vậy nghiệm là x = -1
 

Cảm ơn bạnh nha. Chúc bạn buổi tối ấm =)))) <3

Tập xác định của phương trình

2

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3

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4

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Nghiệm

phaỉ giải rõ ra bạn nhé !

\(\frac{x-12}{3}=\frac{x+1}{4}\)

=>(x-12).4=(x+1)*3

    4x-48=3x+3

    4x-3x=48+3

    x=51

(x-12)/3=(x+1)/4

(x-12)*4=(x+1)*3

x*4-12*4=x*3+1*3

4x-48=3x+3

4x-3x=3+48

x=51

-=> 4 .(x\(-\)12) = 3 .(x+1)

=.>4x\(-\)48      = 3x+3

=>4x\(-\)3x       = 48 + 3

=.> x                  = 51

Vậy x =51

dễ mà bn

\(\frac{x+4}{2000}+\frac{x+3}{2001}=\frac{x+2}{2002}+\frac{x+1}{2003}\)

\(\Leftrightarrow\frac{x+2004}{2000}+\frac{x+2004}{2001}=\frac{x+2004}{2002}+\frac{x+2004}{2003}\)

\(\Leftrightarrow\left(x+2004\right)\left(\frac{1}{2000}+\frac{1}{2001}-\frac{1}{2002}-\frac{1}{2003}\right)\)

Dễ thấy: \(\left(\frac{1}{2000}+\frac{1}{2001}-\frac{1}{2002}-\frac{1}{2003}\right)\ne0\Rightarrow x+2004=0\Leftrightarrow x=-2014\)

x = -2014

ti-ck nha

.........

\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)

\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}-\frac{x+1}{13}-\frac{x+1}{14}=0\)

\(\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)\left(x+1\right)=0\)

\(\Rightarrow x+1=0\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\ne0\right)\)

\(x=-1\)

Vậy \(x=-1\)