1) (m-4)(m+5)= 2) (3 x-1)(2 x+5)= 3) (3 b^2+2)(2 b+4)= 4) (3 a^2+a)(5 a^2-2 a)= 5)(m+3 n)(m^2-6 m n-n^2)=

1) \( (m-4)(m+5) = m^2 + 5m - 4m - 20 = m^2 + m - 20 \)2) \( (3x-1)(2x+5) = 6x^2 + 15x - 2x - 5 = 6x^2 + 13x - 5 \)3) \( (3b^2+2)(2b+4) = 6b^3 + 12b^2 + 4b + 8 = 6b^3 + 12b^2 + 4b + 8 \)4) \( (3a^2+a)(5a^2-2a) = 15a^4 - 6a^3 + 5a^3 - 2a^2 = 15a^4 - a^3 - 2a^2 \)5) \( (m+3n)(m^2-6mn-n^2) = m^3 - 6m^2n - mn^2 + 3mn^2 - 18mn^2 - 3n^3 = m^3 - 3m^2n - 21mn^2 - 3n^3 \)