3/7x3/13+3/7:13/10+6/14

=3/7x3/13+3/7x10/13+6/14

=3/7x(3/13+10/13)+6/14

=3/7x1+6/14

=3/7+6/14

=3/7+3/7

=6/7

Đề:...........

= 3/7 x 3/13 + 3/7 x 10/13 + 3/7

= 3/7 x (3/13 + 10/13 + 1)

= 3/7 x ( 1 + 1 )

= 3/7 x 2

= 6/7

bằng 1/2 nha

a)1/1/4

b)4/2/5

c)3/8

d)1/2/5

bạn ơi bạn làm kiểu j vậy đến người hk giỏi cx k hiểu

\(\dfrac{2}{5}+\dfrac{3}{7}\)=\(\dfrac{14}{35}\)+\(\dfrac{15}{35}\)=\(\dfrac{29}{35}\)

2/5+1/7x3=2/5+3/7

                =14/35+15/35=29/35

Lời giải:

$\frac{4}{7}\times \frac{3}{5}\times \frac{7}{4}\times 20\times \frac{5}{36}$
$=(\frac{4}{7}\times \frac{7}{4})\times (\frac{3}{5}\times \frac{5}{36})\times 20$

$=1\times \frac{1}{12}\times 20=\frac{20}{12}=\frac{5}{3}$

a) 563 x 23 + 23 x 28 - 23

= 23 x (563 + 28 - 1)

= 23 x 600

= 19200

b) \(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}-1\frac{2}{5}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{7}{5}=2-\frac{7}{5}=\frac{3}{5}\)

c) \(\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times...\times\left(1-\frac{1}{10}\right)=\frac{1}{2}\times\frac{2}{3}\times\frac{3}{4}\times....\times\frac{9}{10}\)

\(=\frac{1\times2\times3\times...\times9}{2\times3\times4\times...\times10}=\frac{1}{10}\)

d) \(\frac{2}{7}\times\frac{3}{9}+\frac{2}{7}\times\frac{2}{3}=\frac{2}{7}\times\left(\frac{3}{9}+\frac{2}{3}\right)=\frac{2}{7}\times1=\frac{2}{7}\)

a ) \(563\cdot23+23\cdot28-23\)

\(=23\cdot\left(563+28-1\right)\)

\(=23\cdot600\)

\(=19200\)

b ) \(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}-1\frac{2}{5}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{7}{5}=2-\frac{7}{5}=\frac{3}{5}\)

c ) \(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot...\cdot\left(1-\frac{1}{10}\right)=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{9}{10}\)

\(=\frac{1\cdot2\cdot3\cdot...\cdot9}{2\cdot3\cdot4\cdot...\cdot10}=\frac{1}{10}\)

d ) \(\frac{2}{7}\cdot\frac{3}{9}+\frac{2}{7}\cdot\frac{2}{3}=\frac{2}{7}\cdot\left(\frac{3}{9}+\frac{2}{3}\right)=\frac{2}{7}\cdot1=\frac{2}{7}\)

a)\(\frac{4}{5}-\frac{1}{4}+\frac{3}{10}\)

\(=\frac{16}{20}-\frac{5}{20}+\frac{6}{20}\)

\(=\frac{17}{20}\)

b) \(\frac{2}{5}:\left(1-\frac{1}{10}\right)\)

\(=\frac{2}{5}:\frac{9}{10}\)

\(=\frac{4}{9}\)

c)\(\frac{7}{8}\times\frac{4}{9}+\frac{1}{14}:\frac{5}{14}\)

\(=\frac{7}{18}+\frac{1}{5}\)

\(=\frac{53}{90}\)

d)\(\frac{2}{7}\times\frac{3}{11}+\frac{2}{7}\times\frac{8}{11}\)

\(=\frac{2}{7}\times\left(\frac{3}{11}+\frac{8}{11}\right)\)

\(=\frac{2}{7}\times1=\frac{2}{7}\)

e) \(12+\left(16-11\right)\times4\)

\(=12+20=32\)

f)\(2\frac{3}{7}+1\frac{4}{7}\)

\(=\frac{17}{7}+\frac{11}{7}\)

\(=4\)

g)\(\frac{2}{3}\times\frac{4}{5}+\frac{1}{5}:\frac{9}{11}\)

\(=\frac{8}{15}+\frac{11}{45}\)

\(=\frac{7}{9}\)

h)\(\left(6,2:2+3,7\right):0,2\)

\(=\left(3,1+3,7\right):0,2\)

\(=6,8:0,2=34\)

#H

\(2m^313dm^3=2,013m^3\)

\(1m^320dm^3=1,02m^3\)

\(4m^35dm^3=4,005m^3\)

\(3m^317cm^3=3,000017m^3\)

2m³ 13dm³ = 3,3m³

1m³ 20dm³ = 3m³

4m³5dm³ = 4,5m³

3m³17cm³ = 3,17m³