Решить (n-m)(n+m) (x-y)(x+y) (a+b)(a-b (2-a)(a+2) (a-7)(7+a) (p+5)(p-5) (8c-9d)(8c+9d) (n-3m)(n+3m) (7x-3y)(7x+3y) (5n-8m)(5n+8m) (x+2y)(x-2y) (x²+5)(x²-5) (a-1)(a+1)

1) n^2-m^2
2)x^2-y^2
3)a^2-b^2
4)(2-a)(2+a)=4-a^2
5)(a-7)(a+7)=a^2-49
6)p^2-5^2=p^2-25
7)(8c)^2-(9d)^2=64c^2-81d^2
8)n^2-(3m)^2
9)(7x)^2-(3y)^2=49x^2-9y^2
10)(5n)^2-(8m)^2=25n^2-64m^2
11)x^2-(2y)^2=x^2-4y^2
12)(x^2)^2-5^2=x^4-25
13)a^2-1^2=a^2-1