Упр.880 ГДЗ Ткачёва 5 класс (Математика)

Найти значение $$y$$, если:

1. а) $$\left(1\frac{1}{14}+\frac{13}{14}\right)+y=4-\frac{9}{14}$$;
   б) $$\left(8\frac{5}{7}-1\frac{6}{7}\right)-y=3-\frac{4}{7}$$;
   в) $$y-\left(2\frac{3}{17}-1\frac{8}{17}\right)=4\frac{5}{17}+1\frac{12}{17}$$;
   г) $$y+\left(4\frac{30}{41}+1\frac{20}{41}\right)=8\frac{2}{41}-1\frac{5}{41}$$.

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) $$1 \frac{29}{41}$$.