Найдите корень уравнения:
1) 0,4x(5x − 6) + 7,2 = 2x(x + 0,6);
2) $x(3x + 2) - 9(x^2 - 7x) = 6x(10 - x)$;
3) $12(x^3 - 2) - 7x(x^2 - 1) = 5x^3 + 2x + 6$.
0,4x(5x − 6) + 7,2 = 2x(x + 0,6)
$2x^2 - 2,4x + 7,2 = 2x^2 + 1,2x$
$2x^2 - 2x^2 - 2,4x - 1,2x = -7,2$
−3,6x = −7,2
x = −7,2 : −3,6
x = 2
$x(3x + 2) - 9(x^2 - 7x) = 6x(10 - x)$
$3x^2 + 2x - 9x^2 + 63x = 60x - 6x^2$
$3x^2 + 2x - 9x^2 + 63x - 60x + 6x^2 = 0$
5x = 0
x = 0 : 5
x = 0
$12(x^3 - 2) - 7x(x^2 - 1) = 5x^3 + 2x + 6$
$12x^3 - 24 - 7x^3 + 7x = 5x^3 + 2x + 6$
$12x^3 - 7x^3 + 5x^3 + 7x - 2x = 6 + 24$
5x = 30
x = 30 : 5
x = 6
Пожауйста, оцените решение
