log3 25×log2 27×log5 2^-3=_____
问题描述:
log3 25×log2 27×log5 2^-3=_____
答
=log25/log3 * log27/log2 *log2^-3 / log5
=2log5/log3 * 3log3/log2 *3log2/log5
=6log5/log2 * 3log2/log5=18
答
2lg5/lg3×3lg3/lg2×(-3lg2/lg5)
=-18
答
log3 25×log2 27×log5 2^-3
=(2lg5/lg3)(3lg3/lg2)(-3lg2/lg5)
=2*3*(-3)
=-18