Răspuns :
35a+29a+15-415=6000
64a+15=6000+415
64a+15=6415
64a=6415-15
64a=6400
a=6400:64
a=100
64a+15=6000+415
64a+15=6415
64a=6415-15
64a=6400
a=6400:64
a=100