1)5a²-5b² 2)3m²-3n² 3)7x²-7y² 4)5x²-20y² ПЖ помогите
(5а - 5b) ( 5a +5б) (3m-3n) (3m+3n) (7x - 7y) (7x+7y) (5x - 20y) (5x + 20y)