回答: #a = 60# #b = 15# 説明: 大きい番号= a 小さい数= b #a = 4b# #a-b = b + 30# #a-b-b = 30# #a-2b = 30# #4b-2b = 30# #2b = 30# #b = 30/2# #b = 15# #a = 4xx15# #a = 60#