Lời giải chi tiết:

5 5 5 3 3 3

8-3 =5                8-5=3                8-6=2             8-8=0

8-1-2=5              8-2-3=3             8-5-1=2          8-0=8

8-2-1=5              8-3-2=3              8-1-5=2         8+0=8

a)( \(\dfrac{-8}{40}\)+\(\dfrac{25}{40}\))+(\(\dfrac{-3}{8}\))

=\(\dfrac{17}{40}\)+(\(\dfrac{-3}{8}\))

=\(\dfrac{17}{40}\)+(\(\dfrac{-15}{40}\))

=\(\dfrac{2}{40}\)

=\(\dfrac{1}{20}\)

b)\(\dfrac{-5}{21}\)-(\(\dfrac{16}{21}\)-\(\dfrac{21}{21}\))

=\(\dfrac{-5}{21}\)-\(-5\)

=\(\dfrac{-25}{105}\)-\(\dfrac{-105}{105}\)

=\(\dfrac{16}{21}\)

bằng đây thôi nha mỏi tay quá

c: =3/7(-5/11+6/11)=3/7*1/11=3/77

d:=8/-3(4/3-7/3)=8/3

e: =3,4-5/8-0,4-3/8

=2-1

=1

7 +1 = 8     6 + 2 = 8     5 + 3 = 8     4 + 4 = 8

1 + 7 = 8     2 + 6 = 8     3 + 5 = 8     8 - 4 = 4

8 - 7 = 1     8 - 6 = 2     8 - 5 = 3     8 + 0 = 8

8 - 1 = 7     8 - 2 = 6     8 - 3 = 5     8 - 0 = 8

8             8             8            8         cô ko dạy hả em mà em ko biết

8             8             8            4

1             2            3             8

7             6            5             8

chào bn

Help

2 = 1 + 1     6 = 2 + 4     8 = 5 + 3     10 = 8 + 2

3 = 1 + 2     6 = 3 + 3     8 = 4 + 4     10 = 7 + 3

4 = 3 + 1     7 = 1 + 6     9 = 8 + 1     10 = 6 + 4

4 = 2 + 2     7 = 5 + 2     9 = 6+ 3     10 = 5 + 5

5 = 4 + 1     7 = 4 + 3     9 = 7 + 2     10 = 10 + 0

5 = 3 + 2     8 = 7 + 1     9 = 5 + 4     10 = 0 + 10

6 = 5 + 1     8 = 6 + 2     10 = 9 + 1     1 = 1 + 0

Tiếng  việt  khó .

NHẢM NHÍ

xàm??

.-. ?

spam à

= (1+1+1+1)+(2+2+2)+(3+3+3+3)+(4+4+4+4)+(5+5+5+5)+(6+6+6+6)+(7+7+7+7)+(8+8+8+8)+(9+9+9+9)+10
4 + 6 + 12 + 16 + 20 + 24 + 28 + 32 + 36 + 10 =
= 188

a) \(4\dfrac{3}{8}+5\dfrac{2}{3}\)

\(=\dfrac{35}{8}+\dfrac{17}{3}\)

\(=\dfrac{105}{24}+\dfrac{136}{24}\)

\(=\dfrac{241}{24}\)

b) \(2\dfrac{3}{8}+1\dfrac{1}{4}+3\dfrac{6}{7}\)

\(=\dfrac{19}{8}+\dfrac{5}{4}+\dfrac{27}{7}\)

\(=\dfrac{29}{8}+\dfrac{27}{7}\)

\(=\dfrac{419}{56}\)

c) \(2\dfrac{3}{8}-1\dfrac{1}{4}+5\dfrac{1}{3}\)

\(=\dfrac{19}{8}-\dfrac{5}{4}+\dfrac{16}{3}\)

\(=\dfrac{9}{8}+\dfrac{16}{3}\)

\(=\dfrac{155}{24}\)

d) \(\left(\dfrac{5}{2}+\dfrac{1}{3}\right):\left(1-\dfrac{1}{2}\right)\)

\(=\dfrac{17}{6}:\dfrac{1}{2}\)

\(=\dfrac{17}{6}\cdot2\)

\(=\dfrac{17}{3}\)

e) \(\left(\dfrac{5}{2}-\dfrac{1}{3}\right)\cdot\dfrac{9}{2}-\dfrac{6}{7}\)

\(=\dfrac{13}{6}\cdot\dfrac{9}{2}-\dfrac{6}{7}\)

\(=\dfrac{39}{4}-\dfrac{6}{7}\)

\(=\dfrac{249}{28}\)

a: =4+3/8+5+2/3

=9+9/24+16/24

=9+25/24

=216/24+25/24=241/24

b: \(=\dfrac{19}{8}+\dfrac{5}{4}+\dfrac{27}{7}=\dfrac{19+10}{8}+\dfrac{27}{7}\)

=27/7+29/8

=419/56

c: =2+3/8-1-1/4+5+1/3

=6+3/8-1/4+1/3

=6+3/8+1/12

=144/24+9/24+2/24

=155/24

d: =(15/6+2/6):1/2

=17/6*2

=17/3

e: =(15/6-2/6)*9/2-6/7

=13/6*9/2-6/7

=117/12-6/7

=249/28

14dm5cm=14,5dm;3dm7cm=3,7dm

chu vi hình chữ nhật đó là:

(14,5+3,7)x2=36,4(dm)

ĐS:36,4dm

14 dm 5 cm = 14,5 dm 

3 dm 7 cm = 3,7 dm 

Chiều rộng HCN là :

14,5 - 3,7 = 10,8 ( dm )

chu vi HCN là :

( 14,5 + 10,8 ) x 2 = 50,6 ( dm )

ĐS:..

ban lam sai roi