A + B =  1 + ( − 3 ) + 5 + ( − 7 ) + ... + 17   +   ( − 2 ) + 4 + ( − 6 ) + 8 + ... + ( − 18 )

= -2 + (-2) +….+(-2) + 2+2+…………+2 = 0

 A= 1+(-3)+5+(-7)+...+17 = (1+(-3))+(5+(-7))+(9+(-11)+(13+(-15))+17 = (-2) + (-2) +(-2) + (-2) + 17 = (-2).4 + 17 = -8+17 = 9

;B= -2+4+(-6)+8+...+(-18) = ((-2)+4)+((-6)+8)+((-10)+12)+((-14)+16)+(-18) = 2+2+2+2+(-18) = 8 + (-18) = -10

Vậy A + B = 9 + (- 10) = -1

a: 10/3-8/3=2/3

11/4-5/4=6/4=3/2

32/17+21/17=53/17

b: 5/6+7/8=20/24+21/24=41/24

3/7-5/14=6/14-5/14=1/14

7/4-3/5=35/20-12/20=23/20

a: 10/3-8/3=2/3

11/4-5/4=6/4=3/2

32/17+21/17=53/17

b: 5/6+7/8=20/24+21/24=41/24

3/7-5/14=6/14-5/14=1/14

7/4-3/5=35/20-12/20=23/20

a: 10/3-8/3=2/3

11/4-5/4=6/4=3/2

32/17+21/17=53/17

b: 5/6+7/8=20/24+21/24=41/24

3/7-5/14=6/14-5/14=1/14

7/4-3/5=35/20-12/20=23/20

a: \(\left(-17\right)+5+\left(-8\right)+17\)

\(=\left(-17+17\right)+\left(5-8\right)\)

=0-3

=-3

b: \(\left(-9\right)+\left(-11\right)+21+\left(-1\right)\)

\(=\left(-9-1\right)+\left(21-11\right)\)

=10-10

=0

c: \(15+23+\left(-25\right)+\left(-23\right)\)

\(=\left(15-25\right)+\left(23-23\right)\)

=-10+0

=-10

d: \(\left(-3\right)+\left(-350\right)+\left(-7\right)+350\)

\(=\left(-3-7\right)+\left(-350+350\right)\)

=-10+0

=-10

e: \(\left(-3\right)+\left(-250\right)+\left(-7\right)+250\)

\(=\left(-3-7\right)+\left(-250+250\right)\)

=-10+0

=-10

f: \(\left(-4\right)+\left(-440\right)+\left(-6\right)+440\)

\(=\left(-4-6\right)+\left(-440+440\right)\)

=-10+0

=-10

g: \(483+\left(-56\right)+263+\left(-64\right)\)

\(=\left(483+263\right)+\left(-56-64\right)\)

\(=746-110=636\)

h: \(215+43+\left(-215\right)+\left(-25\right)\)

\(=\left(215-215\right)+\left(43-25\right)\)

=0+18

=18

a. (-17) + 5 + (-8) + 17

= [5 + (-8)] + [(-17) + 17]

= -3

b. (-9) + (-11) + 21 + (-1)

= [(-9) + (-1)] + [21 + (-11)]

= -10 + 10

= 0

c. 15 + 23 + (-25) + (-23)

= [15 + (-25)] + (23 - 23)

= -10

d. (-3) + (-350) + (-7) + 350

= [(-3) + (-7)] + [(-350) + 350]

= -10

e. (-3) + (-250) + (-7) + 250

= [(-3) + (-7)] + [(-250) + 250]

= -10

f. (-4) + (-440) + (-6) + 440

= [(-4) + (-6)] + [(-440) + 440]

= -10

g. 483 + (-56) + 263 + (-64)

= (483 + 263) + [(-56) + (-64)]

= 746 + (-120)

= 626

h. 215 + 43 + (-215) + (-25)

= [215 + (-215)] + [43 + (-25)]

= 18

a) (-17) + 5 + (-8) + 17

= [5 + (-8)] + [(-17) + 17]

= -3

b) (-9) + (-11) + 21 + (-1)

= [(-9) + (-1)] + [21 + (-11)]

= -10 + 10

= 0

c) 15 + 23 + (-25) + (-23)

= [15 + (-25)] + (23 - 23)

= -10

d) (-3) + (-350) + (-7) + 350

= [(-3) + (-7)] + [(-350) + 350]

= -10

e) (-3) + (-250) + (-7) + 250

= [(-3) + (-7)] + [(-250) + 250]

= -10

f) (-4) + (-440) + (-6) + 440

= [(-4) + (-6)] + [(-440) + 440]

= -10

g) 483 + (-56) + 263 + (-64)

= (483 + 263) + [(-56) + (-64)]

= 746 + (-120)

= 626

h) 215 + 43 + (-215) + (-25)

= [215 + (-215)] + [43 + (-25)]

= 18

Ghi đầy đủ nha

bn có thể ghi rõ ràng đc ko?

a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\) 

=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\) 

=\(0+\dfrac{5}{13}\) 

=\(\dfrac{5}{13}\)

   \(\dfrac{3}{17}\) .\(\dfrac{6}{29}\) - \(\dfrac{3}{17}\).\(\dfrac{35}{29}\) + 2022\(\dfrac{3}{17}\)

= (\(\dfrac{3}{17}\).\(\dfrac{6}{29}\) - \(\dfrac{3}{17}\).\(\dfrac{35}{29}\)) + 2022 + \(\dfrac{3}{17}\)

= \(\dfrac{3}{17}\).(\(\dfrac{6}{29}\) - \(\dfrac{35}{29}\)) + 2022 + \(\dfrac{3}{17}\)

= \(\dfrac{3}{17}\).(-1) + 2022 + \(\dfrac{3}{17}\)

 = (- \(\dfrac{3}{17}\) + \(\dfrac{3}{17}\)) + 2022

= 0 + 2022

= 2022 

b; \(\dfrac{5}{6}\) - (\(\dfrac{1}{3}\) + \(\dfrac{1}{2}\)).20%

= \(\dfrac{5}{6}\) - \(\dfrac{5}{6}\).\(\dfrac{1}{5}\)

= \(\dfrac{5}{6}-\dfrac{1}{6}\)

= \(\dfrac{4}{6}\) 

= \(\dfrac{2}{3}\)

1.

a, Ta có 28=14⇒14+56=1312(Bn tự quy đồng lên nhé !)

b,Ta có1216=34⇒18+34=78(Bn tự quy đồng lên nhé !)

c,Ta có636=16⇒14+16=512(Bn tự quy đồng lên nhé !)

d,Ta có1218=23⇒23+14=1112(Bn tự quy đồng lên nhé !)

7.Phần này mk chỉ cho đáp án thuia.67     ;     

 b,420=15     ;         

c,615       ;            

d,129

a) 1-2-3+4+5-6-7+8+......+17-18-19+20=(1-2-3+4)+(5-6-7+8)+....+(17-18-19+20)

                                                              =0+0+......+0

                                                              =0

câu b hơi khó  mình cần thời gian ,mai mình đưa kết  quả cho

bạn ơi mk đang cần gấp