Упр.354 Часть 2 ГДЗ Виленкин Жохов 6 класс (Математика)
а) -5 7/10 + 3 14/15;
б) 3 5/12 — 4 9/16;
в) -3 1/6 — 1 3/4;
г) -5 7/8 + 9/10;
д) 2 3/8 + 3 5/12 — 6 3/16;
е) 3 4/15 — 8 1/12 + 1 7/30;
ж) 3 1/2 — 2 5/6 — 1 4/9;
з) 5 1/4 — 2 1/12 — 4 2/3.
а) Приведём дробные части к общему знаменателю:
$$ -5\frac{7}{10}+3\frac{14}{15} =-5\frac{21}{30}+3\frac{28}{30} $$
$$ =-(4\frac{51}{30}-3\frac{28}{30}) =-1\frac{23}{30} $$
б)
$$ 3\frac{5}{12}-4\frac{9}{16} =3\frac{20}{48}-4\frac{27}{48} =-1\frac{7}{48} $$
в)
$$ -3\frac{1}{6}-1\frac{3}{4} =-3\frac{2}{12}-1\frac{9}{12} =-4\frac{11}{12} $$
г)
$$ -5\frac{7}{8}+\frac{9}{10} =-5\frac{35}{40}+\frac{36}{40} =-4\frac{75}{40}+\frac{36}{40} =-4\frac{39}{40} $$
д)
$$ 2\frac{3}{8}+3\frac{5}{12}-6\frac{3}{16} =2\frac{18}{48}+3\frac{20}{48}-6\frac{9}{48} $$
$$ =5\frac{38}{48}-5\frac{57}{48} =-\frac{19}{48} $$
е)
$$ 3\frac{4}{15}-8\frac{1}{12}+1\frac{7}{30} =\left(3\frac{8}{30}+1\frac{7}{30}\right)-8\frac{1}{12} $$
$$ =4\frac{15}{30}-8\frac{1}{12} =4\frac{1}{2}-8\frac{1}{12} $$
$$ =4\frac{6}{12}-7\frac{13}{12} =-3\frac{7}{12} $$
ж)
$$ 3\frac{1}{2}-2\frac{5}{6}-1\frac{4}{9} =3\frac{3}{6}-2\frac{5}{6}-1\frac{4}{9} $$
$$ =2\frac{6}{9}-1\frac{4}{9} =\frac{2}{3}-1\frac{4}{9} =\frac{6}{9}-1\frac{4}{9} =-\frac{7}{9} $$
з)
$$ 5\frac{1}{4}-2\frac{1}{12}-4\frac{2}{3} =\left(5\frac{3}{12}-2\frac{1}{12}\right)-4\frac{2}{3} $$
$$ =3\frac{2}{12}-4\frac{2}{3} =3\frac{1}{6}-4\frac{2}{3} =-1\frac{1}{2} $$
Ответ
а) $$-1\frac{23}{30}$$; б) $$-1\frac{7}{48}$$; в) $$-4\frac{11}{12}$$; г) $$-4\frac{39}{40}$$; д) $$-\frac{19}{48}$$; е) $$-3\frac{7}{12}$$; ж) $$-\frac{7}{9}$$; з) $$-1\frac{1}{2}$$.
