a) 9 + 13x = 35 + 26x; 7 2 6) x + 3 = x + 5; 9 3

a) 9 + 13x = 35 + 26x;

1. 9 + 13x = 35 + 26x;
2. 13x - 26x = 35 - 9;
3. -13x = 26;
4. x = 26 : (-13);
5. x = -2.

6) \frac{7}{9}x + 3 = \frac{2}{3}x + 5;

1. \frac{7}{9}x + 3 = \frac{2}{3}x + 5;
2. \frac{7}{9}x - \frac{2}{3}x = 5 - 3;
3. \frac{7}{9}x - \frac{2 \cdot 3}{3 \cdot 3}x = 2;
4. \frac{7}{9}x - \frac{6}{9}x = 2;
5. \frac{1}{9}x = 2;
6. x = 2 : \frac{1}{9};
7. x = 2 \cdot 9;
8. x = 18.

Ответ: a) -2; б) 18