7в кубе-6,5в квадрате

х=163-63+21                                     х=37-20-10

х=121                                               х=7

(121-21)+63=163                              (37-7)-20=10 

х=100+10-60                                    х=170-132-20

х=50                                                х=18

(60+50)-10=100                               (132+18)+20=170

х=210-60-110                                  112-х=130-30

х=40                                                112-х=100

210-(60+40)=110                              х=112-100

                                                        х=12

                                                       (112-12)+30=130

Решение внизу страницы на картинке