Ineed some algebraic so i don't fail.

(x-y)^2 +4xy = (x+y)^2

FOIL

x^2 -2xy+y^2 +4xy = (x+y)^2             x^2 -2xy

Combine like terms

x^2 +2xy +y^2 =  (x+y)^2                   x^2 +2xy

Factor

(x+y)^2 = (x+y)^2                                 (x+y)^2  

step-by-step explanation:

i found the koficent of the linear function and i foun c acordind to the strict formula y=kx+c and then i took 2 as an x and replacet it on the formula i found and then foun the y