Упростить выражения: a) -8ac ⋅ (-a ⋅ b); b) -(0,5xy^3) ⋅ 0,6x^2y^5.

a) -8ac ⋅ (-a ⋅ b) = 8a^2bc. b) -(0,5xy^3) ⋅ 0,6x^2y^5 = -0,3x^3y^8.