1) (x - y)(x + y) = x² - y²
2) (b - a)(b + a) = b² - a²
3) (2x - 1)(2x + 1) = 4x² - 1
4) (n - 3m)(3m + n) = (n - 3m)(n + 3m) = n² - 9m²
5) (10x - 7y)(10x + 7y) = 100x² - 49y²
1) (x - y)(x + y) = x² - y²
2) (b - a)(b + a) = b² - a²
3) (2x - 1)(2x + 1) = 4x² - 1
4) (n - 3m)(3m + n) = (n - 3m)(n + 3m) = n² - 9m²
5) (10x - 7y)(10x + 7y) = 100x² - 49y²