Răspuns:
Explicație pas cu pas:
713x + 311 = 734x
734x - 713x = 311
21x = 311
x = 311/21 ∉ N
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33x + 228 = 57x + 356
57x - 33x = 228 - 356
24x = -128
x = -128/24 = -16/3 ∉ N
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15x + 418 = 14x + 427
15x - 14x = 427 - 418
x = 9 ∈ N
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(400 + 441)x = 31*841
841x = 31*841
x = 31*841/841 = 31 ∈ N