1) а²-b²+2(a+b)² = (а-b)(а+b)+2(a+b)² = (a+b)·(a-b+2a+2b)=
= (a+b)·(3a+b)
2) b²-c²-10(b-c)² = (b-c)(b+c) - 10(b-c)²= (b-c)·(b+c-10b+10c)=
= (b-c)·(11c-9b)
3) 2(x-y)² + 3x²-3y² = 2(x-y)² + 3(x²-y²) = 2(x-y)² + 3(x-y)·(x+y) =
= (x-y)·(2x-2y+3x+3y) = (x-y)·(5x+y)
4) 5a²-5-4(a+1)² = 5(a²-1) - 4(a+1)² = 5(a-1)·(a+1) - 4(a+1)² =
= (a+1)·(5a-5 - 4a-4) = (a+1)·(a-9)