Выполните умножения: 1) (5m-1)(m+1) 2) (2b+3)(3b-2) 3) (4n+7)(2n-3) 4) (7z-2)(z-3).

(5m-1)(m+1) = 5m^2 + 4m - 1

(2b+3)(3b-2) = 6b^2 + 5b - 6

(4n+7)(2n-3) = 8n^2 + 2n - 21

(7z-2)(z-3) = 7z^2 - 23z + 6