Question

What is the factoring quadratic expression for 125x^2-100x+20=0

Answer 1

$125x^2-100x+20=0\\\\5(25x^2-20x+4)=0\\\\5[(5x)^2-2\cdot5x\cdot2+2^2]=0\\\\5\cdot(5x-2)^2=0\\\\5(5x-2)(5x-2)=0\iff5x-2=0\\\\5x=2\ \ \ \ /:5\\\\x=0.4$

Answer 2

$125x^2-100x+20=0\ /:5\\\\25x^2-20x+4=0\ \ \ \Leftrightarrow\ \ \ (5x)^2-2\cdot5x\cdot2+2^2=0\\\\(5x-2)^2=0\ \ \ \Leftrightarrow\ \ \ 5x-2=0\ \ \ \Leftrightarrow\ \ \ 5x=2\ /:5\ \ \ \Leftrightarrow\ \ \ x=0.4$