3log75 - 3 log 12 - 3 log4 + 3 log16

3log75 - 3 log 12 - 3 log4 + 3 log16 =
3log75 + 3 log 16 - 3 log4 - 3 log12 =
3log(3×25)+3log(4^2)-3log4-3log(3×4) =
3log3+3log(5^2)+2(3log4)-3log4-3log3-
3log4 =
3log(5^2)+3log3-3log3+2(3log4)-3log4-
3log4 =
2(3log5)+0+2(3log4)-2(3log4) =
2(3log5)+0+0 =
2(3log5)

Semoga benar, maaf kalau salah