(a²-25)(a²+25)= (a-5)(a+5)(a²+25)
(x-4)^2-x^2=12
x^2-8x+4-x^2=12
-8x+4=12
-8x=8
x=-1
25y^2-1-(5y-2)^2=0
25y^2-1-(25y^2-20y+4=0
25y^2-1-25y^2+20y-4=0
-1+20y-4=0
-5+20y=0
20y=5
y=4
2(x2-y2)+x-y=2(x-y)(x+y)+x-y=(x-y)(2(x+y)+1)
решение задания смотри на фотографии