Составьте схему вычисления выражения и найдите его значение: a) (24 ⋅ 258 : 43 + 4590 : 102 – 20) : 13; б) (372 + 118 ⋅ 6) : (38 ⋅ 35 – 34 ⋅ 37) – 12.

a) (24 ⋅ 258 : 43 + 4590 : 102 – 20) : 13;

1) $$24 \cdot 258 = 6192$$

    258
 x 24
 ------
  1032
+516
------
6192

2) $$6192 : 43 = 144$$

     144
43|6192
  43
  ----
  189
  172
  ----
   172
   172
   ----
     0

3) $$4590 : 102 = 45$$

    45
102|4590
   408
   -----
   510
   510
   -----
     0

4) $$144 + 45 = 189$$

  144
+ 45
-----
189

5) $$189 - 20 = 169$$

 189
- 20
----
169

6) $$169 : 13 = 13$$

   13
13|169
  13
 ---
  39
  39
 ---
  0

б) (372 + 118 ⋅ 6) : (38 ⋅ 35 – 34 ⋅ 37) – 12.

1) $$118 \cdot 6 = 708$$

   118
 x  6
 ----
   708

2) $$372 + 708 = 1080$$

  372
+708
----
1080

3) $$38 \cdot 35 = 1330$$

  38
x 35
----
 190
+114
----
1330

4) $$34 \cdot 37 = 1258$$

  34
x 37
----
 238
+102
----
1258

5) $$1330 - 1258 = 72$$

1330
-1258
----
  72

6) $$1080 : 72 = 15$$

   15
72|1080
  72
 ---
  360
  360
 ---
   0

7) $$15 - 12 = 3$$

 15
-12
----
 3

Ответ: a) 13; б) 3.