Verified answer

- 2x(x² - x + 3) + x(2x⁵ + x - 5) = - 2x³ + 2x² - 6x + 2x⁶ +x² - 5x =

= 2x⁶ - 2x³ + 3x² - 11x

x = 3  

2 * 3⁶ - 2 * 3³ + 3 * 3² - 11 * 3 = 1458 - 54 + 27 - 33 = 1398