544. Упростите выражение: a) 2/9 x+4/9 x; б) 6/7 a-9/14 a; в) 7/12 m-5/12 m; г) 5/6 b-3/4 b; д) 3 1/2 z+3/2 z; e) 2 3/4 t-1 7/8 t; ж) 2/3 c+1/9 c-7/9 c; з) k-1/7 k; и) 3/11 y+8/11 y; к) 3/5 b + b; л) 5/18 x+(5/12 x-1/4 x); м) 11/18 n-(5/18 n+1/6 n).

544. Упростите выражение:

a) $$ \frac{2}{9}x + \frac{4}{9}x = \frac{2+4}{9}x = \frac{6}{9}x = \frac{2}{3}x $$

Ответ: $$ \frac{2}{3}x $$

б) $$ \frac{6}{7}a - \frac{9}{14}a = \frac{12}{14}a - \frac{9}{14}a = \frac{12-9}{14}a = \frac{3}{14}a $$

Ответ: $$ \frac{3}{14}a $$

в) $$ \frac{7}{12}m - \frac{5}{12}m = \frac{7-5}{12}m = \frac{2}{12}m = \frac{1}{6}m $$

Ответ: $$ \frac{1}{6}m $$

г) $$ \frac{5}{6}b - \frac{3}{4}b = \frac{10}{12}b - \frac{9}{12}b = \frac{10-9}{12}b = \frac{1}{12}b $$

Ответ: $$ \frac{1}{12}b $$

д) $$ 3\frac{1}{2}z + \frac{3}{2}z = \frac{7}{2}z + \frac{3}{2}z = \frac{7+3}{2}z = \frac{10}{2}z = 5z $$

Ответ: $$ 5z $$

e) $$ 2\frac{3}{4}t - 1\frac{7}{8}t = \frac{11}{4}t - \frac{15}{8}t = \frac{22}{8}t - \frac{15}{8}t = \frac{22-15}{8}t = \frac{7}{8}t $$

Ответ: $$ \frac{7}{8}t $$

ж) $$ \frac{2}{3}c + \frac{1}{9}c - \frac{7}{9}c = \frac{6}{9}c + \frac{1}{9}c - \frac{7}{9}c = \frac{6+1-7}{9}c = 0c = 0 $$

Ответ: $$ 0 $$

з) $$ k - \frac{1}{7}k = \frac{7}{7}k - \frac{1}{7}k = \frac{7-1}{7}k = \frac{6}{7}k $$

Ответ: $$ \frac{6}{7}k $$

и) $$ \frac{3}{11}y + \frac{8}{11}y = \frac{3+8}{11}y = \frac{11}{11}y = 1y = y $$

Ответ: $$ y $$

к) $$ \frac{3}{5}b + b = \frac{3}{5}b + \frac{5}{5}b = \frac{3+5}{5}b = \frac{8}{5}b = 1\frac{3}{5}b $$

Ответ: $$ 1\frac{3}{5}b $$

л) $$ \frac{5}{18}x + (\frac{5}{12}x - \frac{1}{4}x) = \frac{5}{18}x + (\frac{5}{12}x - \frac{3}{12}x) = \frac{5}{18}x + \frac{2}{12}x = \frac{5}{18}x + \frac{1}{6}x = \frac{5}{18}x + \frac{3}{18}x = \frac{5+3}{18}x = \frac{8}{18}x = \frac{4}{9}x $$

Ответ: $$ \frac{4}{9}x $$

м) $$ \frac{11}{18}n - (\frac{5}{18}n + \frac{1}{6}n) = \frac{11}{18}n - (\frac{5}{18}n + \frac{3}{18}n) = \frac{11}{18}n - \frac{8}{18}n = \frac{11-8}{18}n = \frac{3}{18}n = \frac{1}{6}n $$

Ответ: $$ \frac{1}{6}n $$