Упр.880 ГДЗ Ткачёва 5 класс (Математика)
1) (1 1/14 + 13/14) + y = 4 — 9/14;
2) (8 5/7 — 1 6/7) — y = 3 — 4/7;
3) y — (2 3/17 — 1 8/17) = 4 5/17 + 1 12/17;
4) y + (4 30/41 + 1 20/41) = 8 2/41 — 1 5/41.
1) $$\left(1 \frac{1}{14}+\frac{13}{14}\right)+y=4-\frac{9}{14}$$
$$1 \frac{1}{14}+\frac{13}{14}=2$$
$$2+y=3 \frac{5}{14}$$
$$y=3 \frac{5}{14}-2=1 \frac{5}{14}$$
2) $$\left(8 \frac{5}{7}-1 \frac{6}{7}\right)-y=3-\frac{4}{7}$$
$$8 \frac{5}{7}-1 \frac{6}{7}=6 \frac{6}{7}$$
$$6 \frac{6}{7}-y=2 \frac{3}{7}$$
$$y=6 \frac{6}{7}-2 \frac{3}{7}=4 \frac{3}{7}$$
3) $$y-\left(2 \frac{3}{17}-1 \frac{8}{17}\right)=4 \frac{5}{17}+1 \frac{12}{17}$$
$$2 \frac{3}{17}-1 \frac{8}{17}=\frac{12}{17}$$
$$4 \frac{5}{17}+1 \frac{12}{17}=6$$
$$y-\frac{12}{17}=6$$
$$y=6+\frac{12}{17}=6 \frac{12}{17}$$
4) $$y+\left(4 \frac{30}{41}+1 \frac{20}{41}\right)=8 \frac{2}{41}-1 \frac{5}{41}$$
$$4 \frac{30}{41}+1 \frac{20}{41}=5 \frac{9}{41}$$
$$8 \frac{2}{41}-1 \frac{5}{41}=6 \frac{38}{41}$$
$$y+5 \frac{9}{41}=6 \frac{38}{41}$$
$$y=6 \frac{38}{41}-5 \frac{9}{41}=1 \frac{29}{41}$$
Ответ
1) $$1 \frac{5}{14}$$; 2) $$4 \frac{3}{7}$$; 3) $$6 \frac{12}{17}$$; 4) $$1 \frac{29}{41}$$.