![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(\dfrac{3}{4}-\dfrac{1}{8}=\dfrac{6}{8}-\dfrac{1}{8}=\dfrac{6-1}{8}=\dfrac{5}{8}\)
b) \(\dfrac{2}{6}-\dfrac{5}{18}=\dfrac{6}{18}-\dfrac{5}{18}=\dfrac{6-5}{18}=\dfrac{1}{18}\)
c) \(\dfrac{2}{5}-\dfrac{3}{20}=\dfrac{8}{20}-\dfrac{3}{20}=\dfrac{8-3}{20}=\dfrac{5}{20}=\dfrac{1}{4}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{5}{12}+\frac{5}{6}-\frac{3}{4}\)
\(=\frac{5}{12}+\frac{10}{12}-\frac{9}{12}\)
\(=\frac{5+10-9}{12}\)
\(=\frac{6}{12}\)
\(=\frac{1}{2}\)
\(\frac{3}{5}+\frac{6}{4}+\frac{5}{2}\)
\(=\frac{24}{40}+\frac{60}{40}+\frac{100}{40}\)
\(=\frac{24+60+100}{40}\)
\(=\frac{184}{40}\)
Tự rứt gọn nha !
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{7}{6}\) + \(\dfrac{5}{12}\) - \(\dfrac{1}{18}\) - 1
= \(\dfrac{42}{36}\) + \(\dfrac{15}{36}\) - \(\dfrac{2}{36}\) - \(\dfrac{36}{36}\)
= \(\dfrac{19}{36}\)
\(\dfrac{13}{6}\) + \(\dfrac{5}{18}+3-\dfrac{7}{12}\)
= \(\dfrac{78}{36}+\dfrac{10}{36}+\dfrac{108}{36}-\dfrac{21}{36}\)
= \(\dfrac{175}{36}\)
3 + \(\dfrac{11}{4}-\dfrac{1}{12}-\dfrac{3}{16}\)
= \(\dfrac{144}{48}+\dfrac{132}{48}-\dfrac{4}{48}-\dfrac{9}{48}\)
= \(\dfrac{263}{48}\)
\(\dfrac{2}{5}\) x \(\dfrac{7}{4}\) - \(\dfrac{2}{5}\) x \(\dfrac{3}{4}\)
= \(\dfrac{2}{5}\) x ( \(\dfrac{7}{4}\) - \(\dfrac{3}{4}\))
= \(\dfrac{2}{5}\) x \(\dfrac{4}{4}\)
= \(\dfrac{2}{5}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a] 4/12 ; 5/12 ; 11/2 ; 1/4
b] 1 ; 9/12; 12/5 ; 11/3
c] 8/21; 6/11;8/7
d] 2/3 ;2/7 15/2
a]1/3 5/12 11/2 1/4
b]1 3/4 12/5 33/9
c]8/21 6/11 8/7
d]2/3 2/7 15/2
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{1}{2}\times\dfrac{3}{4}:\dfrac{6}{5}=\dfrac{3}{8}:\dfrac{6}{5}=\dfrac{5}{16}\)
\(\dfrac{2}{3}+\dfrac{1}{6}:\dfrac{7}{12}=\dfrac{2}{3}+\dfrac{2}{7}=\dfrac{14}{21}+\dfrac{6}{21}=\dfrac{20}{21}\)
\(8\times\dfrac{3}{5}:\dfrac{12}{5}=\dfrac{24}{5}:\dfrac{12}{5}=2\)
\(\dfrac{4}{9}+\dfrac{3}{4}-\dfrac{1}{3}=\dfrac{16}{36}+\dfrac{27}{36}-\dfrac{12}{36}=\dfrac{31}{36}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
1.a,=(54+45+1).113
=100.113
=11300
b,=(3/7+8/14)+(4/9+10/18)
=1+1
=2
2.a,=13/10+1/3
=49/30
b,=12/9.(1/12+1/6)
=12/9.1/4
=1/3
c,=3/4.3/2
=9/8
d,=3/2-1/3
=7/6
1:tính bằng cách thuận tiện nhất:
a)54 x 113 + 45 x 113 + 113
= 54 x 113 + 45 x 113 + 113x1
=113 x(54+45+1)
= 113x100
=1300
b)3/7 + 4/9 + 8/14 + 10/18
=(3/7+8/14)+(4/9+10/18)
= 1 + 1
=2
1/2 + 1/3 + 5/12 = 5/4
học tốt
\(\frac{1}{2}+\frac{1}{3}+\frac{5}{12}\)
\(=\frac{6}{12}+\frac{4}{12}+\frac{5}{12}\)
\(=\frac{10}{12}+\frac{5}{12}\)
\(=\frac{5}{4}\)