Bài 2:
a: \(x^2-4x+3=0\)
\(\Leftrightarrow\left(x-1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)
b: \(\left(3x-5\right)^2-\left(x+1\right)^2=0\)
\(\Leftrightarrow\left(3x-5-x-1\right)\left(3x-5+x+1\right)=0\)
\(\Leftrightarrow\left(4x-4\right)\left(2x-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)
Bài 1:
a: \(2x^3-8x=2x\left(x^2-4\right)=2x\left(x-2\right)\left(x+2\right)\)
b: \(x\left(x-y\right)+x^2-y^2\)
\(=x\left(x-y\right)+\left(x-y\right)\left(x+y\right)\)
\(=\left(x-y\right)\left(2x+y\right)\)
b: \(25\left(x+5\right)^2-9\left(x+7\right)^2\)
\(=\left(5x+25\right)^2-\left(3x+21\right)^2\)
\(=\left(5x+25-3x-21\right)\left(5x+25+3x+21\right)\)
\(=\left(2x+4\right)\left(8x+46\right)\)
\(=4\left(x+2\right)\left(4x+23\right)\)
Bài 1. a) = 2x(x^2-4)
= 2x(x-2)(x+2)
b) = x(x-y) + (x-y)(x+y)
= (x-y)(2x+y)
c) = [5(x+5)]^2 - [3(x+7)]^2
= (5x+25+3x+21)(5x+25-3x-21)
= 4(4x + 23)(x+2)
