Решите уравнения:
1) (7x - 5)² + 67x - 49x² = -2;
2) 196x² - (14x + 3)² + 80x = -5;
3) -2,89x² + (1,7x + 2)² + 0,2x = 11.

1)

\[ (7x - 5)^2 + 67x - 49x^2 = -2 \]

Раскроем скобки:

\[ 49x^2 - 70x + 25 + 67x - 49x^2 = -2 \]

\[ -3x + 25 = -2 \]

\[ -3x = -27 \]

\[ x = 9 \]

Ответ: \( x = 9 \).

2)

\[ 196x^2 - (14x + 3)^2 + 80x = -5 \]

\[ 196x^2 - (196x^2 + 84x + 9) + 80x = -5 \]

\[ 196x^2 - 196x^2 - 84x - 9 + 80x = -5 \]

\[ -4x - 9 = -5 \]

\[ -4x = 4 \]

\[ x = -1 \]

Ответ: \( x = -1 \).

3)

\[ -2{,}89x^2 + (1{,}7x + 2)^2 + 0{,}2x = 11 \]

\[ -2{,}89x^2 + (2{,}89x^2 + 6{,}8x + 4) + 0{,}2x = 11 \]

\[ 7x + 4 = 11 \]

\[ 7x = 7 \]

\[ x = 1 \]

Ответ: \( x = 1 \).

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