### Ответ
**1.**
* $450 - 30 \cdot 4 + 70 : 10 = \mathbf{337}$
* $280 : 7 + 160 \cdot 5 + 70 = \mathbf{910}$
* $650 + 350 - 80 : 2 \cdot 5 = \mathbf{800}$
* $180 + 20 \cdot 6 - 75 : 25 = \mathbf{297}$
**2.**
* $980 - (150 + 30) : 30 = \mathbf{974}$
* $1\,600 + (470 - 70) \cdot 3 = \mathbf{2\,800}$
* $400 \cdot 3 - (750 - 550) \cdot 4 = \mathbf{400}$
* $820 + (1\,420 - 1\,400) \cdot 8 = \mathbf{980}$
**3.**
* $(860 + 40) - (560 - 60) : 100 = \mathbf{895}$
* $(920 - 50) + (480 + 24) : 6 = \mathbf{954}$
* $2\,400 - (270 + 30) \cdot (400 - 396) = \mathbf{1\,200}$
* $510 \cdot 6 - (780 - 20) + (230 + 470) = \mathbf{3\,000}$
**4.**
* $24 + 36 : (2 \cdot 3) = 30$
* $(24 + 36) : 2 \cdot 3 = 90$
* $(24 + 36 : 2) \cdot 3 = 126$
* $(20 \cdot 9 - 6) : 3 = 58$
* $20 \cdot (9 - 6 : 3) = 140$
* $20 \cdot (9 - 6) : 3 = 20$
**5 (Таблицы).**
| $a$ | **200** | **200** | 320 |
| :--- | :---: | :---: | :---: |
| $b$ | 80 | 90 | **90** |
| $a + b$ | **280** | 290 | **410** |
| $a - b$ | 120 | **110** | 230 |
| $c$ | 20 | **40** | 80 |
| :--- | :---: | :---: | :---: |
| $d$ | **4** | 5 | **10** |
| $c \cdot d$ | 80 | **200** | **800** |
| $c : d$ | **5** | 8 | 8 |
**6.**
1)
* При $a = 320$: $\quad a + 320 = \mathbf{640}, \quad a - 320 = \mathbf{0}$
* При $a = 400$: $\quad a + 320 = \mathbf{720}, \quad a - 320 = \mathbf{80}$
2)
* При $b = 1$: $\quad 720 \cdot b = \mathbf{720}, \quad 720 : b = \mathbf{720}$
* При $b = 2$: $\quad 720 \cdot b = \mathbf{1\,440}, \quad 720 : b = \mathbf{360}$
**7.**
1)
* $8\,014 - 132 \cdot 54 + 44\,892 : 36 = \mathbf{2\,133}$
* $7\,068 + 93\,840 : 46 - 506 \cdot 18 = \mathbf{0}$
* $1\,285 - 282 \cdot 75 : 47 + 14\,472 : 18 = \mathbf{1\,639}$
2)
* $(47\,868 + 112\,812) : 52 + (27\,333 + 18\,615) : 84 = \mathbf{3\,637}$
* $(40\,600 - 38\,956) \cdot 33 - (15\,100 - 14\,125) \cdot 11 = \mathbf{43\,527}$
* $(576 + 126\,828 : 542) \cdot (406 \cdot 117 - 47\,000) = \mathbf{406\,620}$
* $(199\,430 - 119 \cdot 805) : (148 + 8\,536 : 88) = \mathbf{423}$
---
### Подробное объяснение и решение по действиям
#### Задание 1 (Устные вычисления)
1. $450 - 30 \cdot 4 + 70 : 10 = 450 - 120 + 7 = 330 + 7 = 337$
2. $280 : 7 + 160 \cdot 5 + 70 = 40 + 800 + 70 = 840 + 70 = 910$
3. $650 + 350 - 80 : 2 \cdot 5 = 1\,000 - 40 \cdot 5 = 1\,000 - 200 = 800$
4. $180 + 20 \cdot 6 - 75 : 25 = 180 + 120 - 3 = 300 - 3 = 297$
---
#### Задание 2
1. $980 - (150 + 30) : 30 = 980 - 180 : 30 = 980 - 6 = 974$
2. $1\,600 + (470 - 70) \cdot 3 = 1\,600 + 400 \cdot 3 = 1\,600 + 1\,200 = 2\,800$
3. $400 \cdot 3 - (750 - 550) \cdot 4 = 1\,200 - 200 \cdot 4 = 1\,200 - 800 = 400$
4. $820 + (1\,420 - 1\,400) \cdot 8 = 820 + 20 \cdot 8 = 820 + 160 = 980$
---
#### Задание 3
1. $(860 + 40) - (560 - 60) : 100 = 900 - 500 : 100 = 900 - 5 = 895$
2. $(920 - 50) + (480 + 24) : 6 = 870 + 504 : 6 = 870 + 84 = 954$
3. $2\,400 - (270 + 30) \cdot (400 - 396) = 2\,400 - 300 \cdot 4 = 2\,400 - 1\,200 = 1\,200$
4. $510 \cdot 6 - (780 - 20) + (230 + 470) = 3\,060 - 760 + 700 = 2\,300 + 700 = 3\,000$
---
#### Задание 4 (Расстановка скобок)
* $24 + 36 : (2 \cdot 3) = 24 + 36 : 6 = 24 + 6 = 30$
* $(24 + 36) : 2 \cdot 3 = 60 : 2 \cdot 3 = 30 \cdot 3 = 90$
* $(24 + 36 : 2) \cdot 3 = (24 + 18) \cdot 3 = 42 \cdot 3 = 126$
* $(20 \cdot 9 - 6) : 3 = (180 - 6) : 3 = 174 : 3 = 58$
* $20 \cdot (9 - 6 : 3) = 20 \cdot (9 - 2) = 20 \cdot 7 = 140$
* $20 \cdot (9 - 6) : 3 = 20 \cdot 3 : 3 = 60 : 3 = 20$
---
#### Задание 5 (Заполнение таблиц)
**Первая таблица:**
* Столбец 1: $a = 120 + 80 = 200$; $\quad a + b = 200 + 80 = 280$.
* Столбец 2: $a = 290 - 90 = 200$; $\quad a - b = 200 - 90 = 110$.
* Столбец 3: $b = 320 - 230 = 90$; $\quad a + b = 320 + 90 = 410$.
**Вторая таблица:**
* Столбец 1: $d = 80 : 20 = 4$; $\quad c : d = 20 : 4 = 5$.
* Столбец 2: $c = 8 \cdot 5 = 40$; $\quad c \cdot d = 40 \cdot 5 = 200$.
* Столбец 3: $d = 80 : 8 = 10$; $\quad c \cdot d = 80 \cdot 10 = 800$.
---
#### Задание 6
1) Выражения $a + 320$ и $a - 320$:
* если $a = 320$: $\quad 320 + 320 = 640; \quad 320 - 320 = 0$.
* если $a = 400$: $\quad 400 + 320 = 720; \quad 400 - 320 = 80$.
2) Выражения $720 \cdot b$ и $720 : b$:
* если $b = 1$: $\quad 720 \cdot 1 = 720; \quad 720 : 1 = 720$.
* если $b = 2$: $\quad 720 \cdot 2 = 1\,440; \quad 720 : 2 = 360$.
---
#### Задание 7 (Письменные вычисления)
**Часть 1:**
1. $8\,014 - 132 \cdot 54 + 44\,892 : 36$
* $132 \cdot 54 = 7\,128$
* $44\,892 : 36 = 1\,247$
* $8\,014 - 7\,128 = 886$
* $886 + 1\,247 = 2\,133$
2. $7\,068 + 93\,840 : 46 - 506 \cdot 18$
* $93\,840 : 46 = 2\,040$
* $506 \cdot 18 = 9\,108$
* $7\,068 + 2\,040 = 9\,108$
* $9\,108 - 9\,108 = 0$
3. $1\,285 - 282 \cdot 75 : 47 + 14\,472 : 18$
* $282 \cdot 75 = 21\,150$
* $21\,150 : 47 = 450$
* $14\,472 : 18 = 804$
* $1\,285 - 450 = 835$
* $835 + 804 = 1\,639$
**Часть 2:**
1. $(47\,868 + 112\,812) : 52 + (27\,333 + 18\,615) : 84$
* $47\,868 + 112\,812 = 160\,680$
* $160\,680 : 52 = 3\,090$
* $27\,333 + 18\,615 = 45\,948$
* $45\,948 : 84 = 547$
* $3\,090 + 547 = 3\,637$
2. $(40\,600 - 38\,956) \cdot 33 - (15\,100 - 14\,125) \cdot 11$
* $40\,600 - 38\,956 = 1\,644$
* $1\,644 \cdot 33 = 54\,252$
* $15\,100 - 14\,125 = 975$
* $975 \cdot 11 = 10\,725$
* $54\,252 - 10\,725 = 43\,527$
3. $(576 + 126\,828 : 542) \cdot (406 \cdot 117 - 47\,000)$
* $126\,828 : 542 = 234$
* $576 + 234 = 810$
* $406 \cdot 117 = 47\,502$
* $47\,502 - 47\,000 = 502$
* $810 \cdot 502 = 406\,620$
4. $(199\,430 - 119 \cdot 805) : (148 + 8\,536 : 88)$
* $119 \cdot 805 = 95\,795$
* $199\,430 - 95\,795 = 103\,635$
* $8\,536 : 88 = 97$
* $148 + 97 = 245$
* $103\,635 : 245 = 423$
Премиум
Решебник 2015 №2 / часть 2. страница / 96 
