cum se rezolva ecuatia 7777-(77÷7+a-7777÷7+777)×7=777

Răspuns :

7777-(11+a-1111+777)*7=777  impartim toata ecuatia prin 7

1111-(a-1100+777)=111
1000-(a-1100+777)=0
1000-a+1100-777=0
2100-777=a
1323=a
a=1323