1) 4x - 10 = 3x + 3;
4x - 3x = 3 + 10;
x = 13.
Ответ: 13.
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2) 25 + 5x = - 5x - 13;
5x + 5x = - 13 - 25;
10x = - 38;
x = - 38 ÷ 10;
x = - 3,8.
Ответ: - 3,8.
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3) 5 (2x - 4) - (11 - x) = 5;
10x - 20 - 11 + x = 5;
10x + x = 5 + 20 + 11;
11x = 36
x = 36 ÷ 11;
x = 36/11;
x = 3 3/11.
Ответ: 3 3/11.
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4) - 2 (5 - 2y) + 3 (2 - 5y) = y;
- 10 + 4y + 6 - 15y = y;
4y - y - 15y = 10 - 6;
- 12y = 4;
y = 4 ÷ (- 12);
y = - 4/12;
y = - 1/3.
Ответ: - 1/3.
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5) 1,2 (5a - 6) = - 4 (0,3a - 0,8);
6a - 7,2 = - 1,2a + 3,2;
6a + 1,2a = 3,2 + 7,2;
7,2a = 10,4;
a = 10,4 ÷ 7,2;
a = 10 2/5 ÷ 7 1/5;
a = 52/5 ÷ 36/5;
a = 52/5 × 5/36;
a = 52 × 5/5 × 36;
a = 13 × 1/1 × 9;
a = 13/9;
a = 1 4/9.
Ответ: 1 4/9.
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