Question

Rezolvati ecuatia logaritmica:

$\frac{2lgx}{lg(5x-4)} = 1$

Answer 1

2lgx=lg(5x-4), conditii: x>0, 5x-4>0 si 5x-4≠1 (pentru a nu se anula numitorul ec. date),deci x≠1> Obtinem: lgx²=lg(5x-4) ⇔x²=5x-4, ⇔ x²-5x+4=0 cu singura solutie admisa de conditii x=4.