25-8*3:2+4*4 = 90: (45-39+4) - 25:5 = (15+39) : 9+16:4 = 63:7+2 * (13-7) : 3 = 44 - (63:9) + 5*6 = 23-17 + (42:6) * 3=

Первый пример.

25 - 8 * 3 / 2 + 4 * 4 = 29;

8 * 3 = 24;

24 / 2 = 12;

25 - 12 = 13;

4 * 4 = 16;

13 + 16 = 29.

Второй пример.

90 / (45 - 39 + 4) - 25 / 5 = 4;

45 - 39 = 6;

6 + 4 = 10;

90 / 10 = 9;

25 / 5 = 5;

9 - 5 = 4.

Третий пример.

(15 + 39) / 9 + 16 / 4 = 10;

15 + 39 = 54;

54 / 9 = 6;

16 / 4 = 4;

6 + 4 = 10.

Четвертый пример.

63 / 7 + 2 * (13 - 7) / 3 = 13;

63 / 7 = 9;

13 - 7 = 6;

2 * 6 = 12;

12 / 3 = 4;

9 + 4 = 13.

Пятый пример.

44 - (63 / 9) + 5 * 6 = 67;

63 / 9 = 7;

44 - 7 = 37;

5 * 6 = 30;

37 + 30 = 67.

Шестой пример.

23 - 17 + (42 : 6) * 3 = 27;

42 / 6 = 7;

7 * 3 = 21;

23 - 17 = 6;

6 + 21 = 27.