Răspuns :
n/4+10=20 aducem la numitor comun:
(n+40)/4=20 /·4
n+40=80 /-40
n=40 R. 40
Verificare: 40:4+10=10+10=20
(n+40)/4=20 /·4
n+40=80 /-40
n=40 R. 40
Verificare: 40:4+10=10+10=20