`x/2+x+x/3+x+x+x/4=5 3/4`

`=>3x+x/2+x/3+x/4=23/4`

`=>49/12x=23/4`

`=>x=69/49`

Vậy `x=69/49`

giúp mik với xin các bạn đó mik đnag cần gấp

3) |x(x-4)| = x

\(\Rightarrow\hept{\begin{cases}x\left(x-4\right)=x\\x\left(x-4\right)=-x\end{cases}}\Rightarrow\hept{\begin{cases}x-4=1\\x-4=-1\end{cases}}\Rightarrow\hept{\begin{cases}x=5\\x=3\end{cases}}\)

Vậy x = 3 hoặc x = 5

\(\Rightarrow x+\dfrac{1}{6}=\dfrac{3}{4}\\ \Rightarrow x=\dfrac{7}{12}\)

X+

A. x = 2

B. \(\dfrac{3}{8}=\dfrac{6}{x}\)\(\Leftrightarrow x=\dfrac{6.8}{3}=16\)

C. x = 3

D. \(x=\dfrac{4.6}{8}=3\)

E. \(x=\dfrac{7}{3}\)

G.\(\dfrac{14}{13}=\dfrac{28}{10-x}\)

<=>\(14\left(10-x\right)=364\)

<=> 10 - x = 26 

<=> x = -16 

H. \(3\left(x+2\right)=4\left(x-5\right)\)

<=> 3x + 6  = 4x - 20 

<=> -x = -26

<=> x = 26

K. \(\dfrac{x}{2}=\dfrac{8}{x}\)

<=> \(x^2=16\)

<=> \(\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

M. \(\left(x-2\right)^2=100\)

<=> \(\left[{}\begin{matrix}x-2=10\\x-2=-10\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-8\end{matrix}\right.\)

a=2

b=16

c=3

d=3

mik chỉ biết thế này thôi(ko chắc đúng=3)

\(3^6\cdot45^4-15^{13}\cdot5^{-9}\)

\(=3^6\cdot\left(3^2\cdot5\right)^4-\left(3\cdot5\right)^{13}\cdot5^{-9}\)

\(=3^6\cdot3^8\cdot5^4-3^{13}\cdot5^{13}\cdot5^{-9}=3^{14}\cdot5^4-3^{13}\cdot5^4=3^{13}\cdot5^4\left(3-1\right)=3^{13}\cdot5^4\cdot2\)

\(27^4\cdot25^3+45^6\)

\(=\left(3^3\right)^4\cdot\left(5^2\right)^3+\left(3^2\cdot5\right)^6\)

\(=3^{12}\cdot5^6+3^{12}\cdot5^6=2\cdot3^{12}\cdot5^6\)

Ta có: \(\frac{3^6\cdot45^4-15^{13}\cdot5^{-9}}{27^4\cdot25^3+45^6}\)

\(=\frac{3^{13}\cdot5^4\cdot2}{2\cdot3^{12}\cdot5^6}\)

\(=\frac{3}{5^2}=\frac{3}{25}\)