Разложите на множители.
1) (5x+(x+y))(5x-(x+y)) 2) (10-(3a+7y))(10+(3a+7y)) 4)(a^2-b^2)(a^2+b^2) 5) (a^3-b^3)(a^3+b^3) 6) (a^4-b^4)(a^4+b^4)