log2/3 (16/9) + 2log3 (4/3) log3 (5/3) + log 2/3 (25/9 ) =
log 2/3 [(16 * 25) / (9 * 9) ] + 2 [ log3 4 - log3 3] [ log3 5 - log3 3] =
log 2/3 [ 400 / 81 ] + 2 [ log3 (4) - 1] [ log3 (5) - 1] =
log (400/81) / log(2/3) + 2 [ log3 (4) - 1] [ log3 (5) - 1] =
-3.93872459183223 + 0.24351547 ≈ -3.695