7. Решите уравнение: 1) (x + 2)(x - 3) = 0; 2) (x - 4)(x + 7) = 0; 3) (0,5x - 3)(2,5x + 5) = 0; 4) (0,8x - 4)(3,5x - 7) = 0; 5) 3x(7,5-2,5x) = 0; 6) 2x (4,8-1,2x) = 0.

1. (x + 2)(x - 3) = 0

   x + 2 = 0 или x - 3 = 0

   x = -2 или x = 3

2. (x - 4)(x + 7) = 0

   x - 4 = 0 или x + 7 = 0

   x = 4 или x = -7

3. (0,5x - 3)(2,5x + 5) = 0

   0,5x - 3 = 0 или 2,5x + 5 = 0

   0,5x = 3 или 2,5x = -5

   x = 6 или x = -2

4. (0,8x - 4)(3,5x - 7) = 0

   0,8x - 4 = 0 или 3,5x - 7 = 0

   0,8x = 4 или 3,5x = 7

   x = 5 или x = 2

5. 3x(7,5 - 2,5x) = 0

   3x = 0 или 7,5 - 2,5x = 0

   x = 0 или 2,5x = 7,5

   x = 0 или x = 3

6. 2x(4,8 - 1,2x) = 0

   2x = 0 или 4,8 - 1,2x = 0

   x = 0 или 1,2x = 4,8

   x = 0 или x = 4

Ответ: 1) x = -2, x = 3; 2) x = 4, x = -7; 3) x = 6, x = -2; 4) x = 5, x = 2; 5) x = 0, x = 3; 6) x = 0, x = 4