Question

(x+2)в кубе+3x в квадрате-11=(x+3)в кубе

Answer 1

${(x + 2)}^{3} + {3x }^{2} - 11 = {(x + 3)}^{3} \\ {x}^{3} \times {6x}^{2} + 12x + 8 + { 3x}^{2} - 11 = \\ {x}^{3} + {9x}^{2} + 27x + 27 \\ {9x}^{2} + 12x - 3 = {9x}^{2} + 27x + 27 \\ 12x - 3 = 27x + 27 \\ 12x - 27x = 27 + 3 \\ - 15x = 30 \\ x = 30 \div ( - 15) \\ x = - 2$