Advertisements (Quảng cáo)
Bài 9 Tìm x, biết:
a) x + \(\frac{1}{3} = \frac{3}{4}\)
b) x – \(\frac{2}{5} = \frac{5}{7}\)
d) \(\frac{4}{7} – x = \frac{1}{3}\)
a) x + \(\frac{1}{3} = \frac{3}{4}\) => x = \(\frac{3}{4} – \frac{1}{3} = \frac{9}{12} – \frac{4}{12} = \frac{5}{12}\)
Advertisements (Quảng cáo)
b) x – \(\frac{2}{5} = \frac{5}{7}\) => x = \(\frac{5}{7} + \frac{2}{5} = \frac{25}{35} + \frac{14}{35}= \frac{39}{35} = 1\frac{4}{35}\)
c) -x – \(\frac{2}{3}\) = \(- \frac{6}{7}\) => \(\frac{-2}{3} + \frac{6}{7} = x => x = -\frac{14}{21} + \frac{18}{21} = \frac{4}{21}\)
d) \(\frac{4}{7} – x = \frac{1}{3}\) => \(\frac{4}{7} – \frac{1}{3} = x => x = \frac{12}{21} – \frac{7}{21} = \frac{5}{21}\)