x mm \text { x mm } x mm
(n−1)mm(\mathrm{n}-1 ) \mathrm{mm}(n−1)mm
1n+1 mm\frac{1}{n+1} \mathrm{~mm}n+11 mm
110 nmm\frac{1}{10 \mathrm{\ n}} \mathrm{mm}10 n1mm