Ответ:

1. 3-3.5×2,5=-5,75

2. 8×(- 5,75)=-46

3. -46-20=-66

4.-66+23=-43

Ответ:

24 - 28m - 20 + 23m

24 - 28m - 20 + 23mm = 2.5

24 - 28m - 20 + 23mm = 2.524 - 28 * 2.5 - 20 + 23 * 2.5 = 24 - 70 - 20 + 57.5 = - 8.5

24 - 28m - 20 + 23mm = 2.524 - 28 * 2.5 - 20 + 23 * 2.5 = 24 - 70 - 20 + 57.5 = - 8.5m = 1.2

24 - 28m - 20 + 23mm = 2.524 - 28 * 2.5 - 20 + 23 * 2.5 = 24 - 70 - 20 + 57.5 = - 8.5m = 1.224 - 28 * 1.2 -20 + 23 * 1.2= 24 - 33.6 - 20 + 27.6 = - 2

24 - 28m - 20 + 23mm = 2.524 - 28 * 2.5 - 20 + 23 * 2.5 = 24 - 70 - 20 + 57.5 = - 8.5m = 1.224 - 28 * 1.2 -20 + 23 * 1.2= 24 - 33.6 - 20 + 27.6 = - 2m = 40

24 - 28m - 20 + 23mm = 2.524 - 28 * 2.5 - 20 + 23 * 2.5 = 24 - 70 - 20 + 57.5 = - 8.5m = 1.224 - 28 * 1.2 -20 + 23 * 1.2= 24 - 33.6 - 20 + 27.6 = - 2m = 4024 - 28 * 40 - 20 + 23 * 40= 24 - 1120 - 20 + 920 = - 196 

просто так

1)3.5m+23m=26.5m

2)8 умножить на 3 и минус 20=4

3)26.5 умножаем на 2.5,на 1.2,на 40