Respuesta :

Combine ln 24 - (1/2)ln 9:  That comes out to  ln 24 - ln sqrt(9) = ln 24 - ln 3, which in turn is equal to ln 24/3, or ln 8.

Then ln (k^2 - 1) = ln 8, and  so  k^2 - 1 = 8,   k^2   = 9   and 

k = plus or minus 3.