Ответ:

Решение:

1. (1615 - 2,25) · 0,16 - 0,42 : 0,4

\( 1615 - 2.25 = 1612.75 \)

\( 1612.75 \cdot 0.16 = 258.04 \)

\( 0.42 : 0.4 = 1.05 \)

\( 258.04 - 1.05 = 256.99 \)

2. -0,168 : 1,6 + 0,2 · (0,45 - 54)

\( -0.168 : 1.6 = -0.105 \)

\( 0.45 - 54 = -53.55 \)

\( 0.2 \cdot (-53.55) = -10.71 \)

\( -0.105 + (-10.71) = -0.105 - 10.71 = -10.815 \)

3. -0,54 · (-91) : (4,59 : 4,5 - 1,5) - 2

\( -0.54 \cdot (-91) = 49.14 \)

\( 4.59 : 4.5 = 1.02 \)

\( 1.02 - 1.5 = -0.48 \)

\( 49.14 : (-0.48) = -102.375 \)

\( -102.375 - 2 = -104.375 \)

4. -3 + (2,94 : 2,8 - 1,5) · (-91) : (-0,036)

\( 2.94 : 2.8 = 1.05 \)

\( 1.05 - 1.5 = -0.45 \)

\( -0.45 \cdot (-91) = 40.95 \)

\( 40.95 : (-0.036) = -1137.5 \)

\( -3 + (-1137.5) = -3 - 1137.5 = -1140.5 \)

5. (0,02 · 0,01 - 0,01) : 0,25 - 83

\( 0.02 \cdot 0.01 = 0.0002 \)

\( 0.0002 - 0.01 = -0.0098 \)

\( -0.0098 : 0.25 = -0.0392 \)

\( -0.0392 - 83 = -83.0392 \)

6. -43 + 8,5 · (0,021 : 0,01 - 2,51)

\( 0.021 : 0.01 = 2.1 \)

\( 2.1 - 2.51 = -0.41 \)

\( 8.5 \cdot (-0.41) = -3.485 \)

\( -43 + (-3.485) = -43 - 3.485 = -46.485 \)

7. (0,15 - 0,15 · 6,4) : (-83 + 0,175)

\( 0.15 \cdot 6.4 = 0.96 \)

\( 0.15 - 0.96 = -0.81 \)

\( -83 + 0.175 = -82.825 \)

\( -0.81 : (-82.825) \approx 0.009779 \)

8. (1,6 - 2,15 - 0,23) : (3,45 - 343)

\( 1.6 - 2.15 = -0.55 \)

\( -0.55 - 0.23 = -0.78 \)

\( 3.45 - 343 = -339.55 \)

\( -0.78 : (-339.55) \approx 0.002297 \)

Ответ: 1) 256.99; 2) -10.815; 3) -104.375; 4) -1140.5; 5) -83.0392; 6) -46.485; 7) 0.009779; 8) 0.002297.