ГДЗ Математика 6 клас Істер — Вправа 250

Розв'язання

1) $\frac{4}{5} + \frac{3}{7} = \frac{28}{35} + \frac{15}{35} = \frac{43}{35} = 1\frac{8}{35};$

2) $\frac{5}{12} + \frac{9}{20} = \frac{25}{60} + \frac{27}{60} = \frac{52}{60} = \frac{13}{15};$

3) $\frac{5}{18} + \frac{4}{45} = \frac{25}{90} + \frac{8}{90} = \frac{33}{90} = \frac{11}{30};$

4) $\frac{12}{17} + \frac{27}{34} = \frac{24}{34} + \frac{27}{34} = \frac{51}{34} = 1\frac{1}{2};$

5) $\frac{5}{9} - \frac{7}{18} = \frac{10}{18} - \frac{7}{18} = \frac{3}{18} = \frac{1}{6};$

6) $\frac{11}{12} - \frac{1}{4} = \frac{11}{12} - \frac{3}{12} = \frac{8}{12} = \frac{2}{3};$

7) $\frac{8}{21} - \frac{4}{35} = \frac{40}{105} - \frac{12}{105} = \frac{28}{105} = \frac{4}{15};$

8) $\frac{11}{63} - \frac{5}{42} = \frac{22}{126} - \frac{15}{126} = \frac{7}{126} = \frac{1}{18}.$