Răspuns :
m=9d
(d+30)=m/4
d=m/4-30
m-9d=0
d-m/4=-30|*9=)9d-9m/4=-270
Adunam cele doua si eliminam 9dsi -9d
=)m-9m/4=-270|*4
4m-9m=-1080
-5m=-1080m=216
216=9d =)d=216/9=24
(d+30)=m/4
d=m/4-30
m-9d=0
d-m/4=-30|*9=)9d-9m/4=-270
Adunam cele doua si eliminam 9dsi -9d
=)m-9m/4=-270|*4
4m-9m=-1080
-5m=-1080m=216
216=9d =)d=216/9=24
m=9d
d+30=(1/4)(m-30)
=>4d+120=m-30=> 4d+150=m
4d+150=9d=> 150=5d=>d=30 & m=270
d+30=(1/4)(m-30)
=>4d+120=m-30=> 4d+150=m
4d+150=9d=> 150=5d=>d=30 & m=270