Nội dung bài giảng
Bài 1. Tính:
a) \( \frac{7}{9}+\frac{9}{10}\) ; b) \( \frac{5}{6}+\frac{7}{8}\) ; c) \( \frac{3}{5}+\frac{1}{2}+\frac{3}{10}\) .
Bài làm
a) \( \frac{7}{9}+\frac{9}{10}\) \( =\frac{70}{90}+\frac{81}{90}=\frac{151}{90}\) ;
b) \( \frac{5}{6}+\frac{7}{8}\) \( =\frac{40}{48}+\frac{42}{48}=\frac{82}{48}=\frac{41}{24}\) ;
c) \( \frac{3}{5}+\frac{1}{2}+\frac{3}{10}\) \( =\frac{6+5+3}{10}=\frac{14}{10}=\frac{7}{5}\) .