1) 1/15 + 1/12 и 1/2 − 1/12

\(\frac{1}{15}+\frac{1}{12}=\frac{4}{60}+\frac{5}{60}=\frac{9}{60}=\frac{3}{20}\).

\(\frac{1}{2}-\frac{1}{12}=\frac{6}{12}-\frac{1}{12}=\frac{5}{12}\).

Так как \(\frac{3}{20}<\frac{5}{12}\), то \(\frac{1}{15}+\frac{1}{12}<\frac{1}{2}-\frac{1}{12}\).