afla numarul necunoscut.
28+15:a+21:3=38
varog ajutor!


Răspuns :

28+15:a+7=38
28+15:a=38-7=31
15:a=31-28=3
a=15:3
a=5
28+15:a+21:3=38
28+15:a+7=38
28+15:a=38-7
28+15:a=31
15:a=31-28
15:a=3
a=15:3
a=5

VERIFICARE :
28+15:5+21:3=28+3+7
=31+7
=38




SUCCES !