Thanks. Oh..i miss.. only "a" and в.

Б)(24+x)-21=10     24+х=10+21     24+х=31     х=31-24       х=7 ответ: 7. в)(45-у)+18=58     45-у+18=58     -у=45+18-58       -у=5     у=-5 ответ: 5. д)56-(х-15)=24     х+15=56-24     х+15=32     х=32-15       х=17   ответ: 17. е)55-(х-15)=30     55-х+15=30     -х=55+15-30     -х=40     х=-40 ответ: -40.

                                                                                                                                                       1)груша +ананас =920                                                                                                                  2) груша +банан =450                                                                                                                   3) банан +ананас =830                                                                                                          г=920-а; подставим во второе-    920-а+б=450;  470 =а-б;                                               а=470+б470=а+б   -                                                                                                              подставим в третье выражение       830=а+б; 830=470+2б; б=180г=450-б=450-180=270                                                                                                  а=830-180=650                                                                                                                                            ответ: банан весит 180 грамм,  груша 270,  ананас 650