Б. 1)2+(-1)= 2)→음+2층- 3)-1+4= 4)7+(-2)= 5)10+(-3)= Задание 97. Представьте обыкновенную дробь в виде десятичной и выполните действие. 1)+(-1,7) = 2)+(-2,1) = 3)-+0,75 = 4)-4+1,8 = 5)-2,5+3= 6) 0,26+(-20)= 7)-1,2+25 8) 50+(-0,18) = 9)-7+5,30 = 10)-1+0,45 = Задание 98. Представьте десятичную дробь в виде обыкновенной и выполните действие. 1)0.3+-+-+(-3) = 2) 0,4+(-)= 3)+(-0,7) = 4)-+1,3= 5)-1,7+=

Решение заданий Б

В заданиях нужно выполнить действия с рациональными числами.

1. 2\(\frac{5}{9}\) + (-1\(\frac{2}{3}\)) = 2\(\frac{5}{9}\) - 1\(\frac{2}{3}\) = 2\(\frac{5}{9}\) - 1\(\frac{6}{9}\) = \(\frac{23}{9}\) - \(\frac{15}{9}\) = \(\frac{8}{9}\) ≈ 0,89
2. -4\(\frac{2}{15}\) + 2\(\frac{1}{5}\) = -4\(\frac{2}{15}\) + 2\(\frac{3}{15}\) = -\(\frac{62}{15}\) + \(\frac{33}{15}\) = -\(\frac{29}{15}\) = -1\(\frac{14}{15}\) ≈ -1,93
3. -1\(\frac{1}{3}\) + \(\frac{4}{21}\) = -1\(\frac{7}{21}\) + \(\frac{4}{21}\) = -\(\frac{28}{21}\) + \(\frac{4}{21}\) = -\(\frac{24}{21}\) = -\(\frac{8}{7}\) = -1\(\frac{1}{7}\) ≈ -1,14
4. 7\(\frac{1}{11}\) + (-2\(\frac{1}{3}\)) = 7\(\frac{1}{11}\) - 2\(\frac{1}{3}\) = 7\(\frac{3}{33}\) - 2\(\frac{11}{33}\) = \(\frac{232}{33}\) - \(\frac{77}{33}\) = \(\frac{155}{33}\) = 4\(\frac{23}{33}\) ≈ 4,7
5. 1\(\frac{5}{6}\) + (-3\(\frac{1}{4}\)) = 1\(\frac{5}{6}\) - 3\(\frac{1}{4}\) = 1\(\frac{10}{12}\) - 3\(\frac{3}{12}\) = \(\frac{22}{12}\) - \(\frac{39}{12}\) = -\(\frac{17}{12}\) = -1\(\frac{5}{12}\) ≈ -1,42

Решение задания 97

Нужно представить обыкновенную дробь в виде десятичной и выполнить действие.

1. \(\frac{2}{5}\) + (-1,7) = 0,4 + (-1,7) = -1,3
2. \(\frac{3}{5}\) + (-2,1) = 0,6 - 2,1 = -1,5
3. -\(\frac{1}{5}\) + 0,75 = -0,2 + 0,75 = 0,55
4. -\(\frac{1}{4}\) + 1,3 = -0,25 + 1,3 = 1,05
5. -2,5 + \(\frac{3}{4}\) = -2,5 + 0,75 = -1,75
6. 0,26 + (-\(\frac{11}{20}\)) = 0,26 - 0,55 = -0,29
7. -1,2 + \(\frac{3}{25}\) = -1,2 + 0,12 = -1,08
8. \(\frac{3}{50}\) + (-0,18) = 0,06 - 0,18 = -0,12
9. -\(\frac{7}{20}\) + 5,36 = -0,35 + 5,36 = 5,01
10. -1\(\frac{4}{5}\) + 0,45 = -1,8 + 0,45 = -1,35

Решение задания 98

Представьте десятичную дробь в виде обыкновенной и выполните действие.

1. 0,3 + (\(\frac{2}{3}\) - \(\frac{3}{10}\)) = \(\frac{3}{10}\) + \(\frac{2}{3}\) - \(\frac{3}{10}\) = \(\frac{2}{3}\)
2. 0,4 + (-\(\frac{1}{6}\)) = \(\frac{2}{5}\) - \(\frac{1}{6}\) = \(\frac{12}{30}\) - \(\frac{5}{30}\) = \(\frac{7}{30}\)
3. \(\frac{2}{7}\) + (-0,7) = \(\frac{2}{7}\) - \(\frac{7}{10}\) = \(\frac{20}{70}\) - \(\frac{49}{70}\) = -\(\frac{29}{70}\)
4. -\(\frac{2}{11}\) + 1,3 = -\(\frac{2}{11}\) + \(\frac{13}{10}\) = -\(\frac{20}{110}\) + \(\frac{143}{110}\) = \(\frac{123}{110}\) = 1\(\frac{13}{110}\)
5. -1,7 + \(\frac{4}{9}\) = -\(\frac{17}{10}\) + \(\frac{4}{9}\) = -\(\frac{153}{90}\) + \(\frac{40}{90}\) = -\(\frac{113}{90}\) = -1\(\frac{23}{90}\)
6. 2\(\frac{8}{11}\) + (-3,9) = \(\frac{30}{11}\) - \(\frac{39}{10}\) = \(\frac{300}{110}\) - \(\frac{429}{110}\) = -\(\frac{129}{110}\) = -1\(\frac{19}{110}\)
7. -1\(\frac{5}{7}\) + 0,7 = -\(\frac{12}{7}\) + \(\frac{7}{10}\) = -\(\frac{120}{70}\) + \(\frac{49}{70}\) = -\(\frac{71}{70}\) = -1\(\frac{1}{70}\)
8. 8\(\frac{1}{3}\) + (-7,3) = \(\frac{25}{3}\) - \(\frac{73}{10}\) = \(\frac{250}{30}\) - \(\frac{219}{30}\) = \(\frac{31}{30}\) = 1\(\frac{1}{30}\)
9. -2,4 + 3\(\frac{1}{6}\) = -\(\frac{24}{10}\) + \(\frac{19}{6}\) = -\(\frac{144}{60}\) + \(\frac{190}{60}\) = \(\frac{46}{60}\) = \(\frac{23}{30}\)
10. 6,9 + (-4\(\frac{7}{9}\)) = \(\frac{69}{10}\) - \(\frac{43}{9}\) = \(\frac{621}{90}\) - \(\frac{430}{90}\) = \(\frac{191}{90}\) = 2\(\frac{11}{90}\)