Nội dung bài giảng
Bài 1. Tính:
a) \( \frac{6}{7}+\frac{5}{8}\) ; b) \( \frac{3}{5}-\frac{3}{8}\) ; c) \( \frac{1}{4}+\frac{5}{6}\); d) \( \frac{4}{9}-\frac{1}{6}\) .
Bài giải:
a) \( \frac{6}{7}+\frac{5}{8}\) \( =\frac{48}{56}+\frac{35}{56}=\frac{83}{56}\) ;
b) \( \frac{3}{5}-\frac{3}{8}\) \( =\frac{24}{40}-\frac{15}{40}=\frac{9}{40}\) ;
c) \( \frac{1}{4}+\frac{5}{6}\) \( =\frac{6}{24}+\frac{20}{24}=\frac{26}{24}=\frac{13}{12}\) ;
d) \( \frac{4}{9}-\frac{1}{6}\) \( =\frac{24}{54}-\frac{9}{54}=\frac{15}{54}=\frac{5}{18}\)