Вариант 1. 1. Вычислите: 1) −15 + (−28); 2) 3.7 − 4.1; 3) −2.3 + 6.1; 4) −2/5 − 1/3; 5) 5/6 − (−1/4); 6) −1 1/2 + 3/4.

1. \(-15+(-28)=-43\).
2. \(3.7-4.1=-0.4\).
3. \(-2.3+6.1=3.8\).
4. \(-\frac25-\frac13=-\frac6{15}-\frac5{15}=-\frac{11}{15}\).
5. \(\frac56-\left(-\frac14\right)=\frac56+\frac14=\frac{10}{12}+\frac3{12}=\frac{13}{12}\).
6. \(-1\frac12+\frac34=-\frac32+\frac34=-\frac34\).

Ответ: −43; −0.4; 3.8; −11/15; 13/12; −3/4.