a) (3x-5)2 - (x+1)2 =0
\(\Leftrightarrow\left(3x-5+x+1\right)\left[\left(3x-5\right)-\left(x-1\right)\right]=0\)
\(\Leftrightarrow\left(4x-4\right)\left(2x-6\right)=0\)
\(\Leftrightarrow8\left(x-1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x-1=0\\x-3=0\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=1\\x=3\end{array}\right.\)
b) 4x3 - 36x =0
\(\Leftrightarrow4x\left(x^2-9\right)=0\)
\(\Leftrightarrow4x\left(x-3\right)\left(x+3\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}4x=0\\x-3=0\\x+3=0\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}x=0\\x=3\\x=-3\end{array}\right.\)
b) \(4x^3-36x=4x\left(x^2-9\right)=4x\left(x-3\right)\left(x+3\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=0\\x-3=0\\x+3=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=0\\x=3\\x=-3\end{array}\right.\)
a)
\(\Rightarrow\left[\begin{array}{nghiempt}3x-5=x-1\\3x-5=-x-1\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=2\\x=1\end{array}\right.\)
Vậy x = 2 ; x = 1
b)
\(\Rightarrow4x\left(x^2-36\right)=0\)
\(\Rightarrow\left(x-6\right)\left(x+6\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}x-6=0\\x+6=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=6\\x=-6\end{array}\right.\)
Vậy x = 6 ; x = - 6
a) \(\left(3x-5\right)^2-\left(x+1\right)^2=\left(3x-5-x-1\right)\left(3x-5+x+1\right)\)
\(=\left(2x-6\right)\left(4x-4\right)=2\left(x-3\right).4\left(x-1\right)=0\)
\(\Rightarrow\left(x-3\right)\left(x-1\right)=0\Rightarrow\left[\begin{array}{nghiempt}x=3\\x=1\end{array}\right.\)
