Réponses

  • Utilisateur Brainly
2013-11-02T12:36:14+01:00
Log 2^(x+1)+2^(x+3) = log 2^(1-x)+2^(2-x)
donc log 2^(x+1+x+3) = log 2^(1-x+2-x)
donc log 2^(2x+4) = log 2^(-2x+3)
(2x+4) log 2 = (-2x+3) log 2
2x+4 = -2x+3
4x=-1
x= -1/4