Question

Решите Плиз с обьяснением

Answer 1

Ответ:

$7(2 + y) - 3y = 5y - 6 \\ 7 \times 2 + 7y - 3y = 5y - 6 \\ 14 + 7y - 3y = 5y - 6 \\ 7y - 3y - 5y = - 6 - 14 \\ 4 - 5y = - (6 + 14) \\ - y = - 20 \\ \boxed{y = 20}$

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$4x -2 (3 + x) = 9 - x \\ 4x - 2 \times 3 - 2x = 9 - x \\ 4x - 6 - 2x = 9 - x \\ 4x - 2x + x = 9 + 6 \\ 3x = 15 \\ x = 15 \div 3 \\ \boxed{ x=5 }$

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$17 + 3(15 - c) = (4 - c) - 2(c - 5) \\ 17 + 3 \times 15 - 3c = 4 - c - 2c + 2 \times 5 \\ 17 + 45 - 3c = 4 - c - 2c + 10 \\ - 3c + c + 2c = 4 + 10 - 17 - 45 \\ ...= 14 - 62 \\ ... = - 48 \\ = = >$

\boxed{Уравнение не имеет решения}