MatemáticasBásico1 respuestas

Log (x + 2 ) + log ( x - 4 ) = 3 log 3?

Log (x + 2 ) + log ( x - 4 ) = 3 log 3.

5F1f2f3r4

En resumen

Log(x + 2) + log(x - 4) = log 3 ^ 3log(x + 2)(x - 4) = log 27 (x + 2)(x - 4) = 27 x ^ 2 - 2x - 8 = 27 x ^ 2 - 2x - 8 - 27 = 0 x ^ 2 - 2x - 35 = 0 (x - 7)(x + 5) = 0 x1 = 7 x2 = - 5x = 7 verificación log(7 + 2) + log(7 - 4) = log 9 + log 3 = log 9.

Mejor respuesta

Patrickchulo

4

Log(x + 2) + log(x - 4) = log 3 ^ 3log(x + 2)(x - 4) = log 27 (x + 2)(x - 4) = 27 x ^ 2 - 2x - 8 = 27 x ^ 2 - 2x - 8 - 27 = 0 x ^ 2 - 2x - 35 = 0 (x - 7)(x + 5) = 0 x1 = 7 x2 = - 5x = 7 verificación log(7 + 2) + log(7 - 4) = log 9 + log 3 = log 9.

3 = log 3 ^ 3 = 3log3 (ok)x = - 5 verificación log( - 5 + 2) + log( - 5 - 4) = log( - 3) + log( - 9).