[tex]5x(2 {x}^{3} - 3 {x}^{2} + x) = 5x \times 2 {x}^{3} - 5x \times 3 {x}^{2} + 5x \times x = 10 {x}^{4} - 15 {x}^{3} + 5 {x}^{2} [/tex]
[tex] = \frac{8 {x}^{7} + {x}^{2} + 6 {x}^{4} }{ - {x}^{4} } = \frac{ {x}^{2} \times (8 {x}^{3} + x + 6) }{ - {x}^{4} } = - (8 {x}^{3} + x + 6) = - 8 {x}^{3} - x - 6[/tex]