Уравнения 4*(9+7х)+21=393 ,486:(5х+2)=18, н 5(14+б)+6б=158

Question

Уравнения 4*(9+7х)+21=393 ,486:(5х+2)=18, н
5(14+б)+6б=158

Answer 1

4 * (9 + 7х) + 21 = 393                        486 : (5х + 2) = 18

36 + 28х + 21 = 393                            5х + 2 = 486 : 18

28х = 393 - (36 + 21)                          5х = 27 - 2

28х = 336                                            5х = 25

х = 336 : 28                                         х = 25 : 5

х = 12                                                  х = 5

5 * (14 + b) + 6b = 158

70 + 5b + 6b = 158

11b = 158 - 70

11b = 88

b = 88 : 11

b = 8 

Answer 2

1)  36+28х+21=393
    28х+57 = 393
    28х= 393- 57
  28х=336
   х= 336 : 28
  х= 12

2)  5х+2 = 486 : 18
5х + 2 = 27
5х= 27 -2
5х= 25
х= 25 : 5
х= 5

3) 70 + 5б +6б = 158
  70+11б = 158
11б= 158-70
11б=88
б=88 : 11
б=8

Comments

Во втором ошибка: 5х = 27 - 2 = 25; х = 25 : 5 = 5

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посмотри 2 пример изменения

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всех благодарю