7. Решение уравнений:
- \( 3x(x - 7) -x(4 + 3x) = 5 \)
\( 3x^2 - 21x - 4x - 3x^2 = 5 \)
\( -25x = 5 \)
\( x = \frac{5}{-25} = -0.2 \) - \( 5x - x^2 + 3 = x(2 – x) \)
\( 5x - x^2 + 3 = 2x - x^2 \)
\( 5x + 3 = 2x \)
\( 3x = -3 \)
\( x = -1 \)
Ответ: 1) \( x = -0.2 \); 2) \( x = -1 \).