Question

rezolvati in multimea numerelor reale ecuatia log4 (x+3) + log4 (x-3) =2

Answer 1

Răspuns:

CE :x+3>0 => x>-3

x-3>0=> x>3

=> x€(3; inf)

log4 ( (x+3)(x-3) ) = log 4 4²=> x²-9 =16=> x²=25=> x1=5; x2=-5

Doar x=5€(3; inf)

S={5}