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a) \(\dfrac{7}{15}+\dfrac{8}{15}+\dfrac{9}{16}+\dfrac{7}{16}\)

\(=\left(\dfrac{7}{15}+\dfrac{8}{15}\right)+\left(\dfrac{9}{16}+\dfrac{7}{16}\right)\)

\(=1+1\)

\(=2\)

b) \(\dfrac{4}{7}\times\dfrac{5}{6}+\dfrac{4}{7}\times\dfrac{1}{6}\)

\(=\dfrac{4}{7}\times\left(\dfrac{5}{6}+\dfrac{1}{6}\right)\)

\(=\dfrac{4}{7}\times1\)

\(=\dfrac{4}{7}\)

30 tháng 3 2022

(7/15 + 8 / 15 ) + ( 9/16 +7/16)

1 + 1

2

4/7 . ( 5/6+1/6)

4/7 . 1

4/7

16 tháng 3 2020

Làm 1 câu

10/3...>...1/3

Mấy câu ssu tự quy đồng hay gì gì đấy!

16 tháng 3 2020

10/3.>..1/3.     10/6.>..3/8.     17/4.>..5/6.    1/3..<.5/9     5/8.<..7/5    3/4..<.15/6      10/9.>..10/11   7/8..<.7/2       15/9.>..3/8  15/7.>..15/8      16/5.>..16/7    25/11..<.1

16 tháng 4 2022

Giải chi tiết cho mình nha

2/5 + 11/15 = 17/15
7/8 - 7/9 = 7/72
11/13 x 26/31 = 22/31
16/24 : 4 = 1/6
30 : 6/5 = 25
9/16 : 4 = 9/64
1/2 : 1/3 x 8/15 = 3/2 x 8/15 = 4/5

24 tháng 5 2016

a 7/15 + (5/6 - 1/3) = 7/15 + 1/2 = 14/30 + 15/30 = 29/30

b 4/7 *21/16 : 5/8 = 3/4  : 5/8 = 6/5

c 15/8 - 4/9 * 6/8+ 1/6 =15/8 - 1/3 + 1/6 = 37/24 + 1/6 = 41/24

d 5/12+(3/4 + 2/3 ) : 34/3 =

24 tháng 5 2016

a/\(\frac{7}{15}+\left(\frac{5}{6}-\frac{1}{3}\right)=\frac{7}{15}+\frac{1}{2}=\frac{29}{30}\)

b/\(\frac{4}{7}\cdot\frac{21}{16}:\frac{5}{8}=\frac{4}{7}\cdot\frac{2}{16}\cdot\frac{8}{5}=\frac{4}{35}\)

c/\(\frac{15}{8}-\frac{4}{9}\cdot\frac{6}{8}+\frac{1}{6}=\frac{15}{8}-\frac{1}{3}+\frac{1}{6}=\frac{41}{24}\)

d/ \(\frac{5}{12}+\left(\frac{3}{4}+\frac{2}{3}\right):\frac{34}{3}=\frac{5}{12}+\frac{17}{12}:\frac{34}{3}=\frac{5}{12}+\frac{1}{8}=\frac{13}{24}\)

29 tháng 4 2019

#) Giải :

a) \(\frac{5}{6}\)x  \(\frac{6}{7}\)x  \(\frac{7}{8}\):  \(\frac{15}{16}\)=  \(\frac{5}{8}\):   \(\frac{15}{16}\)=  \(\frac{5}{8}\)x   \(\frac{16}{15}\)=  \(\frac{80}{120}\)=  \(\frac{4}{5}\)

b) \(\frac{4}{7}\)x  \(\frac{7}{10}\)x   \(\frac{3}{4}\) :  \(\frac{9}{20}\)=  \(\frac{2}{5}\)x   \(\frac{3}{4}\)\(\frac{9}{20}\)=  \(\frac{3}{10}\):  \(\frac{9}{20}\)=  \(\frac{60}{90}\)\(\frac{2}{3}\)

#) Chúc bn học tốt :D

\(=\frac{5x6x7}{6x7x8}x\frac{16}{15}\\ =\frac{5}{8}x\frac{16}{15}\\ =\frac{2}{3}\)

b)\(=\frac{4x7x3}{7x10x4}x\frac{20}{9}\\ =\frac{3}{10}x\frac{20}{9}\\ =\frac{2}{3}\)

b)\(=\frac{4x7x3}{7x10x4}x\frac{20}{9}\\ =\frac{3}{10}x\frac{20}{9}\\ =\frac{2}{3}\)

29 tháng 4 2019

\(\frac{5}{6}\times\frac{6}{7}\times\frac{7}{8}:\frac{15}{16}\)

\(=\frac{5}{6}\times\frac{6}{7}\times\frac{7}{8}\times\frac{16}{15}\)

\(=\frac{1}{1}\times\frac{1}{1}\times\frac{1}{1}\times\frac{2}{15}\)

\(=\frac{2}{15}\)

a: \(\dfrac{5}{3}\cdot\dfrac{7}{10}=\dfrac{5}{10}\cdot\dfrac{7}{3}=\dfrac{14}{3}>2\)

\(\dfrac{5}{7}:\dfrac{7}{10}=\dfrac{5}{7}\cdot\dfrac{10}{7}=\dfrac{50}{49}< 2\)

=>\(\dfrac{5}{3}\cdot\dfrac{7}{10}>\dfrac{5}{7}:\dfrac{7}{10}\)

b: \(\dfrac{4}{5}\cdot\dfrac{5}{6}=\dfrac{4}{6}=\dfrac{2}{3}\)

\(\dfrac{8}{9}:\dfrac{4}{3}=\dfrac{8}{9}\cdot\dfrac{3}{4}=\dfrac{8}{4}\cdot\dfrac{3}{9}=\dfrac{2}{3}\)

Do đó: \(\dfrac{4}{5}\cdot\dfrac{5}{6}=\dfrac{8}{9}:\dfrac{4}{3}\)

c: \(\dfrac{5}{11}\cdot\dfrac{33}{15}=\dfrac{5}{15}\cdot\dfrac{33}{11}=\dfrac{3}{3}=1\)

\(\dfrac{6}{17}\cdot\dfrac{34}{25}=\dfrac{34}{17}\cdot\dfrac{6}{25}=2\cdot\dfrac{6}{25}=\dfrac{12}{25}< 1\)

=>\(\dfrac{5}{11}\cdot\dfrac{33}{15}>\dfrac{6}{17}\cdot\dfrac{34}{25}\)

d: \(\dfrac{15}{19}\cdot\dfrac{38}{5}=\dfrac{15}{5}\cdot\dfrac{38}{19}=3\cdot2=6\)

\(\dfrac{15}{16}:\dfrac{3}{8}=\dfrac{15}{16}\cdot\dfrac{8}{3}=\dfrac{15}{3}\cdot\dfrac{8}{16}=\dfrac{5}{2}\)<6

=>\(\dfrac{15}{19}\cdot\dfrac{38}{5}>\dfrac{15}{16}:\dfrac{3}{8}\)

4 tháng 2 2018

a)    \(\frac{3}{16}+\frac{4}{15}+\frac{5}{16}+\frac{1}{15}\)

\(=\left(\frac{3}{16}+\frac{5}{16}\right)+\left(\frac{4}{15}+\frac{1}{15}\right)\)

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

\(=\frac{5}{6}\)

b)   \(\frac{6}{7}\times\frac{8}{15}\times\frac{7}{6}\times\frac{15}{16}\)

\(=\left(\frac{6}{7}\times\frac{7}{6}\right)\times\left(\frac{8}{15}\times\frac{15}{16}\right)\)

\(=1\times\frac{1}{2}=\frac{1}{2}\)

c)   \(\frac{19}{20}\times\frac{13}{21}+\frac{9}{20}\times\frac{8}{21}\)

\(=\frac{19\times13}{20\times21}+\frac{9\times8}{20\times21}\)

\(=\frac{247}{420}+\frac{72}{420}\)

\(=\frac{319}{420}\)

4 tháng 2 2018

còn phần D đâu bn 

a: Đ

b: S

c: S

d: 88/66=44/33=4/3

9 tháng 5 2019

\(\frac{3}{5}\times\frac{6}{7}+\frac{3}{5}:7+\frac{6}{5}\)

\(=\frac{3}{5}\times\frac{6}{7}+\frac{3}{5}\times\frac{1}{7}+\frac{6}{5}\)

\(=\frac{3}{5}\times\left(\frac{6}{7}+\frac{1}{7}\right)+\frac{6}{5}\)

\(=\frac{3}{5}\times1+\frac{6}{5}\)

\(=\frac{3}{5}+\frac{6}{5}=\frac{9}{5}\)

~ Hok tốt ~

9 tháng 5 2019

\(\frac{29}{12}:\frac{1}{2}-\frac{5}{12}:\frac{1}{2}-\frac{1}{2}\)

\(=\left(\frac{29}{12}-\frac{5}{12}\right):\frac{1}{2}-\frac{1}{2}\)

\(=2:\frac{1}{2}-\frac{1}{2}\)

\(=4-\frac{1}{2}=\frac{7}{2}\)

~ Hok tốt ~