(x - y)² - 4a²b² what is this. i'm stuckkk. h€l₱ |\/|€ ₱l$

This is an expression called 'the difference of 2 squares' since each term is a perfect square.  I guess you want to factor it.

in simplest form  difference  can be written as a^2 - b^2 = (a + b)(a - b)

so if we let a = x - y and b = 2ab  we have  

(x - y)^2 - 4a^2b^2  =  ( x - y + 2ab)(x - y - 2ab)