
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.



a. (7/15 + 8/15) + (22/12 + 2/12)
= 1 + 24/12
= 1 + 2
=3
b.(9/7 + 5/7) + (16/20 + 4/20)
= 14/7 + 20/20
= 2 + 1
= 3
\(a,\dfrac{7}{15}+\dfrac{22}{12}+\dfrac{8}{15}+\dfrac{2}{12}\\ =\left(\dfrac{7}{15}+\dfrac{8}{15}\right)+\left(\dfrac{22}{12}+\dfrac{2}{12}\right)\\ =\dfrac{15}{15}+\dfrac{24}{12}\\ =1+2\\ =3\\ b,\dfrac{9}{7}+\dfrac{16}{20}+\dfrac{4}{20}+\dfrac{5}{7}\\ =\left(\dfrac{9}{7}+\dfrac{5}{7}\right)+\left(\dfrac{16}{20}+\dfrac{4}{20}\right)\\ =\dfrac{14}{7}+\dfrac{20}{20}\\ =2+1\\ =3\)

\(\dfrac{3}{9}+\dfrac{9}{15}+\dfrac{16}{24}=\dfrac{1}{3}+\dfrac{9}{15}+\dfrac{2}{3}=\dfrac{5}{15}+\dfrac{9}{15}+\dfrac{10}{15}=\dfrac{24}{15}=\dfrac{8}{5}\)
\(\dfrac{4}{10}+\dfrac{12}{32}+\dfrac{9}{15}=\dfrac{2}{5}+\dfrac{3}{8}+\dfrac{3}{5}=\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{3}{8}=\dfrac{5}{5}+\dfrac{3}{8}=1+\dfrac{3}{8}=1\dfrac{3}{8}=\dfrac{11}{8}\)
\(\dfrac{1}{6}+\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{18}=\dfrac{3}{18}+\dfrac{9}{18}+\dfrac{6}{18}+\dfrac{1}{18}=\dfrac{19}{18}\)

a: =(21/11+12/11)-(9/19+3/19+6/19)=3-18/19=39/19
b: =(2/3+4/3)+(3/4+7/4)+(4/5+16/5)
=2+4+10/4
=6+5/2
=17/2

Bài 1: Tính
\(a.\frac{15}{16}-\frac{7}{16}=\frac{15-7}{16}=\frac{8}{16}=\frac{1}{2}\)
\(b.\frac{7}{4}-\frac{3}{4}=\frac{7-3}{4}=\frac{4}{4}=1\)
\(c.\frac{9}{5}-\frac{3}{5}=\frac{9-3}{5}=\frac{6}{5}\)
\(d.\frac{17}{49}-\frac{12}{49}=\frac{17-12}{49}=\frac{5}{49}\)
Bài 2:Rút gọn rồi tính
\(a.\frac{2}{3}-\frac{3}{9}=\frac{2}{3}-\frac{1}{3}=\frac{2-1}{3}=\frac{1}{3}\)
\(b.\frac{7}{5}-\frac{15}{25}=\frac{7}{5}-\frac{3}{5}=\frac{7-3}{5}=\frac{4}{5}\)
Học tốt. K cho mik nha

a, 21/11-9/19-3/13-12/38-24/22 =21/11-(9/19-3/13)-12/38-24/22 =207/143-12/38-24/22 =3075/2717-24/22 =111/2717 b,2/3+3/4+4/5+12/9+28/16+48/15 =17/12+4/5+12/9+28/16+48/15 =133/60+12/9+28/16+48/15 =71/20+28/16+48/15 =53/10+48/15 =17/2 c, 4/5-1/2-1/4-1/8-1/16-1/36 =3/10-1/4-1/8-1/36 =1/20-1/8-1/16-1/36 =-3/40-1/16-1/36 =-11/60-1/36=-119/720

a)
`7/12+3/4xx2/9`
`=7/12+1/6`
`=7/12+2/12`
`=9/12`
`=3/4`
b)
`8/9-4/15:2/5`
`=8/9-4/15xx5/2`
`=8/9-2/3`
`=8/9-6/9`
`=2/9`

a: \(=\dfrac{21}{11}+\dfrac{12}{11}+\left(-\dfrac{9}{19}-\dfrac{3}{19}-\dfrac{6}{19}\right)=3-\dfrac{18}{19}=\dfrac{39}{19}\)
b: \(=\dfrac{2}{3}+\dfrac{4}{3}+\dfrac{3}{4}+\dfrac{7}{4}+\dfrac{4}{5}+\dfrac{16}{5}=2+4+\dfrac{5}{2}=6+\dfrac{5}{2}=\dfrac{17}{2}\)

a: \(\dfrac{7}{4}-\dfrac{11}{8}+\dfrac{1}{2}\)
\(=\dfrac{14-11+4}{8}\)
\(=\dfrac{7}{8}\)
b: \(\dfrac{3}{16}+\dfrac{7}{30}\cdot\dfrac{40}{36}\)
\(=\dfrac{3}{16}+\dfrac{7}{36}\cdot\dfrac{40}{30}\)
\(=\dfrac{3}{16}+\dfrac{7}{36}\cdot\dfrac{4}{3}\)
\(=\dfrac{3}{16}+\dfrac{7}{27}=\dfrac{81+112}{432}=\dfrac{193}{432}\)
c: \(\left(\dfrac{9}{2}-\dfrac{15}{4}\right):\dfrac{21}{12}\)
\(=\left(\dfrac{18}{4}-\dfrac{15}{4}\right):\dfrac{7}{4}\)
\(=\dfrac{3}{4}\cdot\dfrac{4}{7}=\dfrac{3}{7}\)

12/16= bé hơn 1
4/3 = lớn hơn 1
7/9 = bé hơn 1
15/15 = 1
Vậy ta so sánh phân số nào lớn hơn 1 thì nó lớn nhất
Phân số lớn nhất : 4/3
4 + ( 12/15 : 9/2 ) * 15/16
= 4 + ( 12/15 * 2/9 ) *15/16
= 4 + 1/6
= 25/6
25/6 nhé