(х + 20) * 45 = 3 105
х + 20 = 3 105 : 45
х + 20 = 69
х = 69 - 20
х = 49
(49 + 20) * 45 = 3 105
69 * 45 = 3 105
3 105 = 3 105
х : 34 = 17 000 + 204
х : 34 = 17 204
х = 17 204 * 34
х = 584 936
584 936 : 34 = 17 000 + 204
17 204 = 17 204
57 * (500 - х) = 11 457
500 - х = 11 457 : 57
500 - х = 201
х = 500 - 201
х = 299
57 * (500 - 299) = 11 457
57 * 201 = 11 457
11 457 = 11 457
16 912 : х = 7 890 - 7 834
16 912 : х = 56
х = 16 012 : 56
х = 302
16 012 : 302 = 7 890 - 7 834
56 = 56
