\(7,5-3\left|5-2x\right|=4,5\)

\(\Rightarrow3\left|5-2x\right|=12\)

\(\Rightarrow\left|5-2x\right|=4\)

\(\Rightarrow\orbr{\begin{cases}5-2x=4\\5-2x=-4\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}2x=1\\2x=9\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=\frac{9}{2}\end{cases}}\)

\(2\left|2x-3\right|=\frac{1}{2}\)

\(\Rightarrow\left|2x-3\right|=\frac{1}{4}\)

\(\Rightarrow\orbr{\begin{cases}2x-3=\frac{1}{4}\\2x-3=\frac{-1}{4}\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}2x=\frac{13}{4}\\2x=\frac{11}{4}\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x=\frac{13}{8}\\x=\frac{11}{8}\end{cases}}\)

\(\left|3x-4\right|+\left|3y-5\right|=0\)

Ta có: \(\hept{\begin{cases}\left|3x-4\right|\ge0\\\left|3y-5\right|\ge0\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}\left|3x-4\right|=0\\\left|3y-5\right|=0\end{cases}\Rightarrow\hept{\begin{cases}3x-4=0\\3y-5=0\end{cases}}}\Rightarrow\hept{\begin{cases}3x=4\\3y=5\end{cases}}\Rightarrow\hept{\begin{cases}x=\frac{4}{3}\\y=\frac{5}{3}\end{cases}}\)

\(\left(x+\frac{3}{20}\right)^4=\left(\frac{4}{15}\right)^4\)

\(\Rightarrow x+\frac{3}{20}=\frac{4}{15}\)

\(x=\frac{4}{15}-\frac{3}{20}\)

\(x=\frac{1}{12}\)

---> 2x = 5/2 + 1/2

---> 2x = 3

---> x = 3/2

xin tiick

\(\rightarrow\)2x = \(\frac{5}{2}\) + \(\frac{1}{2}\)

\(\rightarrow\)2x = 3

\(\rightarrow\) \(\frac{3}{2}\)

          ~ Hok Tốt ~

63=3².7

14=2.7

70=2.5.7

=> ƯCLN (63;14;70) = 7

\(A=\left|x\right|+x\)

Trường hợp 1: \(x\ge0\Rightarrow\left|x\right|=x\Rightarrow A=x+x=2x\)

Trường hợp 2: \(x< 0\Rightarrow\left|x\right|=-x\Rightarrow A=-x+x=0\)

\(B=\left|x\right|-x\)

Trường hợp 1: \(x\ge0\Rightarrow\left|x\right|=x\Rightarrow A=x-x=0\)

Trường hợp 2: \(x< 0\Rightarrow x=\left|-x\right|\Rightarrow A=-x-x=-2x\)

\(C=\left|x-1\right|+x\)

Nếu: \(\orbr{\begin{cases}\left|x-1\right|=x-1\Rightarrow x-1\ge0hayx\ge1\\\left|x-1\right|=-\left(x-1\right)=-x+1\Rightarrow x-1< 0hayx< 1\end{cases}}\)

Trường hợp 1: \(x\ge1\Rightarrow\left|x-1\right|+x=x-1+x=2x-1\)

Trường hợp 2: \(x< 1\Rightarrow\left|x-1\right|+x=-x+1+x=1\)

x = 2,(142857) = 15/7

xin tiick

x=15/7

Có 2 khẳng định đúng :

( 0,75 )³ : 0,75 = ( 0,75 )²

\(\frac{50^3}{125}=\frac{50^3}{5^3}=\left(\frac{50}{5}\right)^3=10^3=1000\)

~~Học tốt~~