Question

помогите под (а ,б) плиз

Answer 1

2,4+х=-2,8                           18,24-у=20
х=-2,8-2,4                            у=18,24-20
х=-5,2                                   у= -1,76
---------                                   -------------
2,4+(-5,2)=-2,8                      18,24-(-1,76)=20
-2,8   =-2,8                              20=20