[tex]( - 6 {a}^{3} b + 2a {b}^{2} )(5 {a}^{2} - 2a {b}^{2} - b) \\ = - 30 {a}^{5} b + 12 {a}^{4} {b}^{3} + 16 {a}^{3} {b}^{2} - 4 {a}^{2} {b}^{4} - 2a {b}^{3} [/tex]
