Explanation:
Since we have given that
[tex](2x+1)^2-2(2x+1)[/tex]
Now, we have to prove it as
[tex](2x+1)(2x-1)[/tex]
Now, start the iterations:
[tex](2x+1)^2-2(2x+1)\\\\=4x^2+1+4x-4x-2\\\\=4x^2+1-2\\\\=4x^2-1\\\\=(2x)^2-1\\\\=(2x+1)(2x-1)[/tex]
So, first blank will be filled with
[tex]4x^2+4x+1[/tex]
Second blank will be filled with
[tex]4x^2-1[/tex]
Hence proved.