А) х*7-80=340 б) (900-y): 9=80 в) (350: y+10)*7=560 решите ) заранее

7х-80=340             900-у=80*9          350:у+10=560:7
7х=340+80            900-у=720           350:у+10=80
7х=420                 у=900-720            350:у=80-10
х=420:7                у=180                  350:у=70
Х=60                                               у=350:70
                                                      у=5