avsirena 7 * (3 + k) = 33 + 5k
21 + 7k = 33 + 5k
7k - 5k = 33 - 21
2k = 12
k = 12 : 2
k = 6
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Проверка: 7 * (3 + 6) = 33 + 5 * 6
                   7 * 9 = 33 + 30
                    63 = 63 

prettypushkova

Verified answer

21+7к=33+57к-5к=33-212к=12К=6