jika nilai 2 log 5 = x dan 3 log 2 = y maka nilai 12 log 10 adalah...

log10/log12=log(2×5)/log(3×4)
=log2+log5/log3+log4
=log2+log5/log3+2×log2
=2log2+2log5/2log3+2×2log2
=1+x / 1/y+2×1
=1+x / 1/y+2
=1+x / 1+2y/y
=(1+x)y/1+2y
=y+xy/1+2y