Вычислите: а) 26 + (−6); б) −70 + 50; в) −17 + 30; г) 80 + (−120); д) −6,3 + 7,8; е) −9 + 10,2; ж) 1 + (−0,39); з) 0,3 + (−1,2); и) 5/9 + (−8/9); к) 3/4 + (−2/3); л) −5/8 + 3/4; м) −4/5 + 2/3; н) −3 3/4 + 2 1/2; о) −3/8 + 5 1/16; п) 2 4/7 + (−3 5/14); р) 5 4/9 + (−5 4/9).

1. \(26+(-6)=20\).
2. \(-70+50=-20\).
3. \(-17+30=13\).
4. \(80+(-120)=-40\).
5. \(-6.3+7.8=1.5\).
6. \(-9+10.2=1.2\).
7. \(1+(-0.39)=0.61\).
8. \(0.3+(-1.2)=-0.9\).
9. \(\frac{5}{9}+\left(-\frac{8}{9}\right)=\frac{5-8}{9}=-\frac{3}{9}=-\frac{1}{3}\).
10. \(\frac{3}{4}+\left(-\frac{2}{3}\right)=\frac{9-8}{12}=\frac{1}{12}\).
11. \(-\frac{5}{8}+\frac{3}{4}=-\frac{5}{8}+\frac{6}{8}=\frac{1}{8}\).
12. \(-\frac{4}{5}+\frac{2}{3}=\frac{-12+10}{15}=-\frac{2}{15}\).
13. \(-3\frac{3}{4}+2\frac{1}{2}=-\frac{15}{4}+\frac{10}{4}=-\frac{5}{4}=-1\frac{1}{4}\).
14. \(-\frac{3}{8}+5\frac{1}{16}=-\frac{6}{16}+\frac{81}{16}=\frac{75}{16}=4\frac{11}{16}\).
15. \(2\frac{4}{7}+\left(-3\frac{5}{14}\right)=\frac{36}{14}-\frac{47}{14}=-\frac{11}{14}\).
16. \(5\frac{4}{9}+\left(-5\frac{4}{9}\right)=0\).

Ответ: 20; −20; 13; −40; 1,5; 1,2; 0,61; −0,9; −1/3; 1/12; 1/8; −2/15; −1 1/4; 4 11/16; −11/14; 0.