Question

Rút gọn rồi tính:

28/35+21/28+7/21+1/7

Answer 1

28/35+21/28+7/21+1/7

=4/5+3/4+1/3+1/7

=851/420

Answer 2

dùng máy tính là ok mà bn.

Answer 3

\(\frac{28}{35}+\frac{21}{28}+\frac{9}{21}+\frac{1}{7}\)

\(=(\frac{4}{5}+\frac{3}{4})+(\frac{3}{7}+\frac{1}{7})\)

\(=\frac{31}{20}+\frac{4}{7}\)

\(=2\frac{17}{140}\)

Chúc bn học tốt!!!!