Bài 2:

\(B=\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).......\left(1-\frac{1}{2004}\right)\)

\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{2003}{2004}\)

\(=\frac{1}{2004}\)

Bài 2

=1/2 x 2/3 ... x 2003/2004

=1/2004

2.

1/2004

sudy well

study well

`a, (2 \times 6) \times 4`

`= 12 \times 4=48`

`2 \times (6 \times 4)`

`= 2 \times 24 = 48`

` (8 \times 5) \times 2`

`= 40 \times 2=80`

` 8 \times (5 \times 2)`

` 8 \times 10 = 80`

`b,` Giá trị của `2` biểu thức `(2 \times 6) \times 4, 2 \times (6 \times 4)`  bằng nhau `(=48)`

`-` Giá trị của `2` biểu thức `(8 \times 5) \times 2, 8 \times (5 \times 2)` bằng nhau `(=80)`

`c,`

` 25 \times (2 \times 2) =25 \times 4 = 100`

` (25 \times 2) \times 2= 50 \times 2 = 100 `

sqr(d) + b = 25 + 16 = 41

c*d + a = 40 + 31 = 71

41 >= 71 → D := FALSE

a)

\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right).\\A = \left( {\frac{{30}}{{15}} + \frac{5}{{15}} - \frac{6}{{15}}} \right) - \left( {\frac{{105}}{{15}} - \frac{9}{{15}} - \frac{{20}}{{15}}} \right) - \left( {\frac{3}{{15}} + \frac{{25}}{{15}} - \frac{{60}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} - \left( {\frac{{ - 32}}{{15}}} \right)\\A = \frac{{29}}{{15}} - \frac{{76}}{{15}} + \frac{{32}}{{15}}\\A = \frac{{ - 15}}{{15}}\\A =  - 1\end{array}\)

b)

\(\begin{array}{l}A = \left( {2 + \frac{1}{3} - \frac{2}{5}} \right) - \left( {7 - \frac{3}{5} - \frac{4}{3}} \right) - \left( {\frac{1}{5} + \frac{5}{3} - 4} \right)\\A = 2 + \frac{1}{3} - \frac{2}{5} - 7 + \frac{3}{5} + \frac{4}{3} - \frac{1}{5} - \frac{5}{3} + 4\\A = \left( {2 - 7 + 4} \right) + \left( {\frac{1}{3} + \frac{4}{3} - \frac{5}{3}} \right) + \left( { - \frac{2}{5} + \frac{3}{5} - \frac{1}{5}} \right)\\A =  - 1 + 0 + 0 =  - 1\end{array}\)

a mod c + d = 7 + 5 = 12

sqrt(b) + c = 4 + 8 = 12

12 >= 12 → C := TRUE

= 2- 31/40 + 3/2

= 49/40      + 3/2

= 109/40

 tk cho mik nha

\(2-\left(\frac{2}{5}+\frac{3}{8}\right)+\frac{3}{2}\)

\(=2-\frac{31}{40}+\frac{3}{2}\)

\(=\frac{49}{40}+\frac{3}{2}\)

\(=\frac{109}{40}\)

ủng hộ tớ nha

a) (2/5 x 25/29) + (3/5 x 25/29)
= (50/145) + (75/145)
= 125/145

b) (5/2 x 3/7) - (3/14 : 6/7)
= 15/14 - (3/14 x 7/6)
= 15/14 - 1/2
= (30/28) - (14/28)
= 16/28
= 4/7

c) (15/4 : 5/12) - (6/5 : 11/15)
= (15/4 x 12/5) - (6/5 x 15/11)
= 180/20 - 90/55
= 9 - 18/11
= (99/11) - (18/11)
= 81/11
= 7 4/11

a) (2/3) + (20/21 x 3/2 x 7/5)
= 2/3 + (60/210)
= 2/3 + 2/7
= (14/21) + (6/21)
= 20/21

b) (5/17 x 21/32 x 47/24 x 0)
= 0

c) (11/3 x 26/7) - (26/7 x 8/3)
= (286/21) - (208/21)
= 78/21
= 3 9/21
= 3 3/7

a) (25/8) : x = 5/16
=> (25/8) x (16/5) = x
=> 4 = x

b) x + (7/15) = 6/15
=> x = (6/15) - (7/15)
=> x = -1/15

c) x : (28/49) = 7/12
=> x x (49/28) = 7/12
=> x = (7/12) x (28/49)
=> x = 1/2

a) 6 x x = (5/8) : (3/4)
=> 6x = (5/8) x (4/3)
=> 6x = 20/24
=> 6x = 5/6
=> x = (5/6) / 6
=> x = 5/36

câu,b,không,đủ,thông,tin,nhan,bạn.

6 : \(\dfrac{5}{2}-\dfrac{3}{10}=\dfrac{12}{5}-\dfrac{3}{10}=\dfrac{21}{10}\)

\(\dfrac{4}{6}:\dfrac{4}{3}+5:\dfrac{4}{3}=\left(\dfrac{4}{6}+5\right):\dfrac{4}{3}=\dfrac{17}{3}:\dfrac{4}{3}=\dfrac{17}{4}\)

a) 6 : 5/2 - 3/10

= 6 x 2/5 - 2/10

= 12/5 - 3/10

=21/10

b) 4/6 : 4/3 + 5 : 4/3

= ( 4/6 + 5) : 4/3

= 17/3 : 4/3

= 17/4

a) 12/5 - 3/10

= 24/10 - 3/10 

= 21/10

b) ( 4/6 + 5 ) : 4/3

= 17/3 : 4/3

= 17/4

a.đáp án:85/8

b.đáp án:97/12

a) = 85/8

b) = 97/12 nha bn

\(a,\frac{35}{4}-\frac{5}{8}+\frac{5}{2}\)

\(=\frac{70}{8}-\frac{5}{8}+\frac{20}{4}\)

\(=\frac{65}{8}+\frac{20}{8}\)

\(=\frac{85}{8}\)

\(b,\frac{15}{2}+\frac{14}{5}:\frac{6}{5}-\frac{7}{4}\)

\(=\frac{15}{2}+\frac{14}{5}.\frac{5}{6}-\frac{7}{4}\)

\(=\frac{15}{2}+\frac{7}{3}-\frac{7}{4}\)

\(=\frac{90}{12}+\frac{28}{12}-\frac{21}{12}\)

\(=\frac{118}{12}-\frac{21}{12}\)

\(=\frac{97}{12}\)