\(\left(\frac{2}{5}+\frac{7}{9}\right)+\frac{3}{5}\)
\(=\left(\frac{2}{5}+\frac{3}{5}\right)+\frac{7}{9}\)
\(=1+\frac{7}{9}=\frac{16}{9}\)
\(\frac{19}{11}+\left(\frac{8}{13}+\frac{3}{11}\right)\)
\(=\left(\frac{19}{11}+\frac{3}{11}\right)+\frac{8}{13}\)
\(=2+\frac{8}{13}=\frac{34}{13}\)
a) \(\left(\frac{2}{5}+\frac{7}{9}\right)+\frac{3}{5}\) = \(\left(\frac{2}{5}+\frac{3}{5}\right)+\frac{7}{9}\)= \(1+\frac{7}{9}\)=\(\frac{16}{9}\).
b) Tương tự, bn tự làm đi nha.
a, =2/5+7/9+3/5
=(2/5+3/5)+7/9
=1+7/9
=16/9
chúc bn hk tốt
a, (2/5+7/9)+3/5
=(2/5+3/5)+7/9
=1+7/9
=16/9
b,19/11+(8/13+3/11)
=(19/11+3/11)+8/13
=2+8/13
=34/13
a, ( 2/5 + 7/9 ) + 3/5 b, 19/11 + ( 8/13 + 3/11 )
= ( 2/5 + 3/5 ) + 7/9 = ( 19/11 + 3/11 ) +8/13
= 5/5 + 7/9 = 22/11 + 8/13
= 1 + 7/9 = 2 + 8/13
= 16/9 = 34/13
Chúc bạn học tốt!~
