23) 1 − 5 1/4 · 1/7 : 3/8 =

5\(\frac{1}{4}\)=\(\frac{21}{4}\); \(\frac{21}{4}\cdot\frac{1}{7}=\frac{3}{4}\); \(\frac{3}{4}:\frac{3}{8}=2\); 1 − 2 = −1.

Ответ: −1