Question

1/ Rút gọn rồi tính :

    A) 3/5 + 2/5         B) 4/6 + 18/27         C) 15/25 + 6/21        

Answer 1

a) 3/5 + 2/5 = 5/5 = 1

b) 4/6 =2/3 ; 18/27 = 2/3

    2/3 + 2/3 = 4/3

c) mình ko biết làm

Answer 2

a) \(\frac{3}{5}+\frac{2}{5}=\frac{3+2}{5}=\frac{5}{5}=1\)

b)\(\frac{4}{6}=\frac{2}{3}\)

\(\frac{18}{27}=\frac{2}{3}\)

\(\frac{2}{3}+\frac{2}{3}=\frac{2+2}{3}=\frac{4}{3}\)

c)\(\frac{15}{25}=\frac{3}{5}\)

\(\frac{6}{21}=\frac{2}{7}\)

\(\frac{3}{5}+\frac{2}{7}=\frac{21}{35}+\frac{10}{35}=\frac{21+10}{35}=\frac{31}{35}\)