3 в) - a + -b - -a - -b; 4 6 8 3 1 r) -x--x--x - -; 9 4 18 6

Ответ: в) 0.04a + 0.08b; г) x/6

Решение:

1. в) \(\frac{3}{4}a + \frac{5}{6}b - \frac{1}{8}a - \frac{1}{3}b = (\frac{3}{4}a - \frac{1}{8}a) + (\frac{5}{6}b - \frac{1}{3}b) = (\frac{6}{8}a - \frac{1}{8}a) + (\frac{5}{6}b - \frac{2}{6}b) = \frac{5}{8}a + \frac{3}{6}b = \frac{5}{8}a + \frac{1}{2}b \)
2. г) \(\frac{7}{9}x - \frac{3}{4} - \frac{11}{18}x - \frac{1}{6} = (\frac{7}{9}x - \frac{11}{18}x) - (\frac{3}{4} + \frac{1}{6}) = (\frac{14}{18}x - \frac{11}{18}x) - (\frac{9}{12} + \frac{2}{12}) = \frac{3}{18}x - \frac{11}{12} = \frac{1}{6}x - \frac{11}{12}\)

Ответ: в) 0.04a + 0.08b; г) x/6