2 a) 4x + 20 = 0; б) \frac{3}{2}x - 6 = 0;

a) 4x + 20 = 0;

1. 4x + 20 = 0;
2. 4x = -20;
3. x = -20 : 4;
4. x = -5.

б) \frac{3}{2}x - 6 = 0;

1. \frac{3}{2}x - 6 = 0;
2. \frac{3}{2}x = 6;
3. x = 6 : \frac{3}{2};
4. x = 6 \cdot \frac{2}{3};
5. x = \frac{6 \cdot 2}{3};
6. x = \frac{12}{3};
7. x = 4.

Ответ: a) -5; б) 4