Question

18x-[5x³+3x³-{2x²-(6-2x-x³)-5x³}-5x³}-3x]​

Answer 1

18x-[5x³+3x³-{2x²-(6-2x-x³)-5x³-5x³}-3x]

18x-[5x³+3x³-{2x²-6+2x+x³-10x³}-3x]

18x-[5x³+3x³-2x²+6-2x+9x³-3x]

18x - [17x³-2x²+6-5x]

18x - 17x³ + 2x² - 6 + 5x

-17x³ + 2x² - 6 + 23x

Answer 2

$18x - (8 {x}^{3} - (6 - 2x - {x}^{3} ) - 10 { x}^{3} - 3x \\ 15x - ( - 19 {x}^{3} - 2x - 6 \\ = - 19 {x}^{3} - \: - 17x - 6$

hope it helps you ✌️✅✅✅