Номер 7 помагите!!!!!!!!!!!!!!!!!!

Question

Номер 7 помагите!!!!!!!!!!!!!!!!!!

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Answer 1

А).
172 + 172 = 344
344 + 172 = 516
516 + 172 = 688
688 + 172 = 860

172 + 172 + 172 + 172 + 172 = 172*(1 + 1 + 1 + 1 + 1) = 172*5 = 860

172 * 5 = (100 + 70 + 2)*5 = 100*5 + 70*5 + 2*5 = 500 + 350 + 10 = 860

б).
123 + 2*123 + 2*123 = 123*(1 + 2 + 2) = 123*5 = 615
123 + 2*123 + 2*123 = 123 + 246 + 246 = 123 + 492 = 615