a) \(\frac{2}{5}+\frac{3}{6}=\frac{12}{30}+\frac{15}{30}\)
\(=\frac{12+15}{30}\)
\(=\frac{27}{30}=\frac{9}{10}\)
b) \(\frac{5}{9}-\frac{1}{6}=\frac{30}{54}-\frac{9}{54}\)
\(=\frac{30-9}{54}\)
\(=\frac{21}{54}=\frac{7}{18}\)
c) \(\frac{3}{4}\times\frac{7}{9}=\frac{3\times7}{4\times9}\)
\(=\frac{27}{36}=\frac{3}{4}\)
d) \(\frac{15}{18}:\frac{3}{36}=\frac{15}{18}\times\frac{36}{3}\)
\(=\frac{15\times36}{18\times3}\)
\(=\frac{540}{54}=10\)
Vậy a) 9/10 b) 7/18 c) 3/4 ; d) 10
ủng hộ nha
a) 2/5+3/6
= 12/30+15/30
=27/30=9/10
b)5/9-1/6
=10/18-3/18
=7/18
c)3/4*7/9
=21/36=7/12
d)15/18:/36
=10/3
2/5 + 3/6 = 12/30 + 15/30 = 27/30 rút gọn = 9/10
5/9 - 1/6 = 30/54 - 9/54 = 21/54 rút gọn = 7/18
3/4 nhân 7/9 = 21/36 rút gọn = 7/13
15/18 chia 9/36 rút gọn hai phân số ta được 5/6 chia 1/4 = 5/6 nhân 4/1 = 20/6 rút gọn = 10/3