Answer:
[tex](2x-1)^2[/tex]
Step-by-step explanation:
[tex]4x^2-4x+1=\\(2x)^2+2(2x)(-1)+(-1)^2\\\\\textrm{Using the rule }A^2+2AB+B^2=(A+B)^2\textrm{, then:}\\(2x)^2+2(2x)(-1)+(-1)^2=(2x-1)^2[/tex]