👤

Va rog cat mai rapid.
5 (x + 2) + 5 = 20


Răspuns :

5 ( x + 2 ) + 5 = 20
5x + 10 + 5 = 20
5x + 15 = 20
5x = 20 - 15
5x = 5 ⇒ x = 5 / 5 ⇒ x = 1

Verificare: 5 
· ( 1 + 2 ) + 5 = 5 · 3 + 5 = 15 + 5 = 20 ( se verifica )
5 (x + 2) + 5 = 20

5x + 10 + 5 = 20

5x = 20 - 10 - 5

5x = 5

x = 1