Question

Din numarul elevilor de clada a iv a au participat la concursuri scolare 3/9 au participat la concursul Cangurul matematician,2/9 au participat la
concursul Proeducatia ,si restul de 12 elevi au participat la concursul Eurojunior .Cati elevi ai claselor a iv a au participat a cele trei concursuri scolare?

Answer 1

a=3/9a+2/9a+12
a=5a/9+12
9a=5a+12x9
4a=108
a=108/4
a=27