Hello, we know that for a and b real numbers
[tex]a^2-b^2=(a-b)(a+b)[/tex]
So,
[tex](2a-b)^2-(a-2b)^2=(2a-b-a+2b)(2a-b+a-2b)\\\\=(a+b)(3a-3b)\\\\\boxed{=3(a+b)(a-b)}[/tex]
Thank you.
