Вычислите: а) −2,301 + 4,2; б) −1,8 − 1 3/8; в) −5/12 − 1/15; г) −1 31/32 + 2 7/24.

1. \( -2{,}301+4{,}2=1{,}899 \).
2. \( -1{,}8-1\frac{3}{8}=-\frac{9}{5}-\frac{11}{8}=-\frac{72}{40}-\frac{55}{40}=-\frac{127}{40}=-3\frac{7}{40} \).
3. \( -\frac{5}{12}-\frac{1}{15}=-\frac{25}{60}-\frac{4}{60}=-\frac{29}{60} \).
4. \( -1\frac{31}{32}+2\frac{7}{24}=-\frac{63}{32}+\frac{55}{24}=-\frac{189}{96}+\frac{220}{96}=\frac{31}{96} \).

Ответ: а) 1,899; б) \(-3\frac{7}{40}\); в) \(-\frac{29}{60}\); г) \(\frac{31}{96}\).