a) 25 : x = x
25 = x^2
x^2 = ( +-5 )^2
b) 3358 : 23 = 2x - 6
146 = 2x - 6
2x = 152
x = 76
c) ( 2x + 1 )^3 = 27 = 3^3
=> 2x + 1 = 3
=> 2x = 2
=> x = 1
d) ( x - 2 )^3 = ( x - 2 )^2
( x - 2 )^2 . ( x - 2 ) - ( x -2 )^2 = 0
( x - 2 )^2 . [ ( x - 2 ) - 1 ] = 0
+) x - 2 = 0
=> x = 2
+) x - 2 - 1 = 0
x - 3 = 0
x = 3
\(25\div x=x\Rightarrow x.x=25\Rightarrow x^2=25\Rightarrow\orbr{\begin{cases}x=5\\x=-5\end{cases}}\)
\(3358\div23=2x-6\)
\(\Rightarrow2x-6=146\)
\(\Rightarrow2x=152\)
\(\Rightarrow x=\frac{152}{2}=76\)
\(\left(2x+1\right)^3=27\)
Mà \(3^3=27\)
Nên \(\left(2x+1\right)^3=3^3\)
\(\Rightarrow2x+1=3\Rightarrow2x=2\Rightarrow x=1\)
\(\left(x-2\right)^3=\left(x-2\right)^2\)
\(\Rightarrow\left(x-2\right)^3-\left(x-2\right)^2=0\)
\(\Rightarrow\left(x-2\right)^2.\left(x-2-1\right)=0\)
\(\Rightarrow\left(x-2\right)^2.\left(x-3\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-2=0\\x-3=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=2\\x=3\end{cases}}}\)
Vậy......................
\(25:x=x\)
\(x^2=25\Leftrightarrow\orbr{\begin{cases}x=5\\x=-5\end{cases}}\)
\(3358:23=2x-6\)
\(\Leftrightarrow2x-6=146\)
\(\Leftrightarrow2x=152\)
\(\Leftrightarrow x=76\)
\(\left(2x+1\right)^3=27\)
\(\Leftrightarrow\left(2x+1\right)^3=3^3\)
\(\Leftrightarrow2x+1=3\)
\(\Leftrightarrow2x=2\)
\(\Leftrightarrow x=1\)
\(\left(x-2\right)^3=\left(x-2\right)^2\)
\(\Rightarrow\left(x-2\right)^3-\left(x-2\right)^2=0\)
\(\Leftrightarrow\left(x-2\right)^2.\left(x-2-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}\left(x-2\right)^2=0\\x-2-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x-2=0\\x-3=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=2\\x=3\end{cases}}}\)
