[tex] \frac{3x - 9}{4} \times 8x = \\ = \frac{3x - 9}{4} \times \frac{8x}{1} = \\ = \frac{3x - 9}{1} \times \frac{2x}{1} = \\ = 2x \times (3x - 9) = \\ = 6 {x}^{2} - 18x \\ \\( 6 {x}^{2} - 18x) \div 3 = \\ = \frac{6 {x}^{2} - 18x }{3} = \\ = \frac{3(2 {x}^{2} - 6x) }{3} = \\ = 2 {x}^{2} - 6x \\ \\ (2 {x}^{2} - 6x )\times \frac{1}{2} x = \\ = \frac{2 {x}^{2} - 6x}{1} \times \frac{x}{2} = \\ = \frac{x(2 {x}^{2} - 6x) }{2} = \\ = \frac{2 {x}^{3} - 6 {x}^{2} }{2} = \\ = \frac{2( {x}^{3} - 3 {x}^{2}) }{2} = \\ = {x}^{3} - 3 {x}^{2} [/tex]
