Question

Решите уравнение срочно 50 баллов
1) x(x^2-2)=x^3+8
2)(x+7)(x-7)-(x-3)^2=53
3) (x-2)^3+(x+2)^3=2x(x^2-1)+3

Answer 1

1)
x^3 - 2x = x^3 + 8
x^3 - 2x - x^3 - 8 = 0
- 2x - 8 = 0
- 2x = 8
2x = - 8
x = - 4

2)
x^2 - 49 - (x^2 - 6x + 9) - 53 = 0
x^2 - 49 - x^2 + 6x - 9 - 53 = 0
- 49 + 6x - 62 = 0
6x - 111 = 0
6x = 111
x = 111/6 = 37/2 = 18,5 

3)
x^3 - 6x^2 + 12x - 8 + x^3 + 6x^2 + 12x + 8 = 2x^3 - 2x + 3 
2x^3 + 24x = 2x^3 - 2x + 3
24x = - 2x + 3
24x + 2x = 3 
26x = 3
x = 3/26