log5 (2x+1) - log5 3 = 3

Răspuns :

CE: 2x+1>0 => x>-1/2
Log5 (2x+1)/3 = log5 5^3
Log5 este functie injectiva
=> (2x+1)/3 = 5^3
2x+1=125×3
2x=375-1
x=374/2
x=187 >-1/2