Ajutor!!!@
Ex 3.112
............
![Ajutor Ex 3112 class=](https://ro-static.z-dn.net/files/d24/45d24360ce1fa4bdb027247ff3a08d0c.jpg)
Notez:
Numărul l a care m am gândit = a
REZOLVARE:
a×5=5a
[ ( 5a + 15 ) :5 ] -5 =5
( 5a + 15 ) :5 = 5+5
( 5a + 15 ) : 5 = 10
5a + 15 = 5 ×10
5a + 15= 50
5a= 50 -15
5a=35
a=35: 5
a= 7
VERIFICARE:
7×5=35
35+15=50
50:5=10
10-5=5
Coroană ?