i)
[tex] - 4x \times (3x + 2) = - 12 {x}^{2} - 8x [/tex]
j)
[tex]7x - (4 + 5 {x}^{2} ) - 3x(2 - 6x) = 7x - 4 - 5 {x}^{2} - 6x + 18 {x}^{2} = 13 {x}^{2} + x - 4[/tex]
k)
[tex](5 - 4x) \times (3x + 2) = 15x + 10 - 12 {x}^{2} - 8x = - 12 {x}^{2} + 13x + 10[/tex]
l)
[tex](x + 6) \times (7 - 2 {x}^{2} ) = 7x - 2 {x}^{3} + 42 - 12 {x}^{2} = - 2 {x}^{3} - 12 {x}^{2} + 7x + 42[/tex]
