Verified answer

[tex]4 \frac{3}{8} - (6.8 + 2 \frac{3}{4} ) = - 5 \frac{7}{40} \\ 1) \: 6.8 + 2 \frac{3}{4} = 6 \frac{4}{5} + 2 \frac{3}{4} = \\ 6 \frac{16}{20} + 2 \frac{15}{20} = 8 \frac{31}{20} = 9 \frac{11}{20} \\ 2) \: 4 \frac{3}{8} - 9 \frac{11}{20} = \\ 4 \frac{15}{40} - 9 \frac{22}{40} = - 5 \frac{7}{40} [/tex]

[tex]0.75 - (0.125 + \frac{3}{4} ) = - 0.125 \\ 1) \: 0.125 + \frac{3}{4} = \frac{1}{8} + \frac{6}{8} = \frac{7}{8} \\2) \: 0.75 - \frac{7}{8} = \frac{3}{4} - \frac{7}{8} = \\ \frac{6}{8} - \frac{7}{8} = - \frac{1}{8} = - 0.125[/tex]

[tex]( \frac{4}{15} + 0.3) - (1 - \frac{3}{20} ) = - \frac{17}{60} \\ 1) \: \frac{4}{15} + \frac{3}{10} = \frac{8}{30} + \frac{9}{30} = \frac{17}{30} \\ 2) \: 1 - \frac{3}{20} = \frac{20}{20} - \frac{3}{20} = \frac{17}{20} \\ 3) \: \frac{17}{30 } - \frac{17}{20} = \frac{34}{60} - \frac{51}{60} = - \frac{17}{60} [/tex]

[tex](0.6 + \frac{3}{4} ) - \frac{7}{20} + 0.7 = \\ 0.6 + 0.75 - 0.35 + 0.7 = \\ 0.6 + 0.4 + 0.7 = \\ 1 + 0.7 = 1.7[/tex]

[tex]( \frac{4}{7} - 0.5) + \frac{5}{14} - 1.4 = - \frac{34}{35} \\ 1) \: \frac{4}{7} - 0.5 = \frac{4}{7} - \frac{1}{2} = \\ \frac{8}{14} - \frac{7}{14} = \frac{1}{14} \\ 2) \: \frac{1}{14} + \frac{5}{14} = \frac{6}{14} = \frac{3}{7} \\ 3) \: \frac{3}{7} - 1.4 = \frac{3}{7} - \frac{7}{5} = \\ \frac{15}{35} - \frac{49}{35} = - \frac{34}{35} [/tex]

[tex]1.725 - (1 \frac{1}{2} + 0.6) - \frac{3}{5} = \\ 1.725 - 1.5 - 0.6 - 0.6 = \\ 1.725 -2 .7 = - 0.975[/tex]

Пошаговое объяснение:

А

1) 6,8 + 2 3/4 = 6 8/10 + 2 3/4 = 6 16/20 + 2 15/20 = 8 31/20 = 9 11/20

2) 4 3/8 - 9 11/20 = 4 15/40 - 9 22/40 = -5 7/40

Б

1) 0,125 + 3/4 = 0,125 + 0,75 = 0,875

2) 0,75 - 0,875 = -0,125

В

1) 4/15 + 0,3 = 4/15 + 3/10 = 8/30 + 9/30 = 17/30

2) 1 - 3/20 = 20/20 - 3/20 = 17/20

3) 17/30 - 17/20 = 34/60 - 51/60 = -17/60

Г

1) 0,6 + 3/4 = 6/10 + 3/4 = 12/20 + 15/20 = 27/20 = 1 7/20

2) 1 7/20 - 7/20 = 1

3) 1 + 0,7 = 1,7

Д

1) 4/7 - 0,5 = 4/7 - 5/10 = 40/70 - 35/70 = 5/70 = 1/14

2) 1/14 + 5/14 = 6/14 = 3/7

3) 3/7 - 1,4 = 3/7 - 1 4/10 = 30/70 - 1 28/70 = 30/70 - 98/70 = -68/70 = -34/35

Е

1) 1 1/2 + 0,6 = 1,5 + 0,6 = 2,1

2) 1,725 - 2,1 = -0,375

3) -0,375 - 3/5 = -0,375 - 0,6 = -0,975