Упр.568 ГДЗ Никольский Потапов 6 класс (Математика)

а) 18 5/9+(-22 2/9);
б) 25 3/4+(-51 1/4);
в)-6 2/9+1 2/3;
г) 7 1/12+(-8 3/4);
д) 18 5/6+(-7 1/2);
е) 2 1/5+(-4/15).

а) $$18\frac{5}{9}+(-22\frac{2}{9})=-(22\frac{2}{9}-18\frac{5}{9})$$

$$=-(4\frac{2}{9}-\frac{5}{9})=-(3+\frac{11}{9}-\frac{5}{9})=-(3+\frac{6}{9})=-(3+\frac{2}{3})=-3\frac{2}{3}$$

б) $$25\frac{3}{4}+(-51\frac{1}{4})=-(51\frac{1}{4}-25\frac{3}{4})$$

$$=-(26\frac{1}{4}-\frac{3}{4})=-(25+\frac{5}{4}-\frac{3}{4})=-(25+\frac{2}{4})=-(25+\frac{1}{2})=-25\frac{1}{2}$$

в) $$-6\frac{2}{9}+1\frac{2}{3}=-(6\frac{2}{9}-1\frac{2}{3})$$

$$=-(6\frac{2}{9}-1\frac{6}{9})=-(5\frac{2}{9}-\frac{6}{9})=-(4+\frac{11}{9}-\frac{6}{9})=-(4+\frac{5}{9})=-4\frac{5}{9}$$

г) $$7\frac{1}{12}+(-8\frac{3}{4})=-(8\frac{3}{4}-7\frac{1}{12})$$

$$=-(8\frac{9}{12}-7\frac{1}{12})=-(1\frac{8}{12})=-1\frac{2}{3}$$

д) $$18\frac{5}{6}+(-7\frac{1}{2})=18\frac{5}{6}-7\frac{1}{2}$$

$$=18\frac{5}{6}-7\frac{3}{6}=11\frac{2}{6}=11\frac{1}{3}$$

е) $$2\frac{1}{5}+ \left(-\frac{4}{15}\right)=2\frac{1}{5}-\frac{4}{15}$$

$$=2\frac{3}{15}-\frac{4}{15}=1+\frac{18}{15}-\frac{4}{15}=1+\frac{14}{15}=1\frac{14}{15}$$

Ответ

а) $$-3\frac{2}{3}$$; б) $$-25\frac{1}{2}$$; в) $$-4\frac{5}{9}$$; г) $$-1\frac{2}{3}$$; д) $$11\frac{1}{3}$$; е) $$1\frac{14}{15}$$.