Ai giúp e đi ak e cần găp

1

100+90+80+70+60+50+40+30+20+10+1+2+3+4+5+6+7+8+9=595

100+90+80+70+60+50+40+30+20+10+1+2+3+4+5+6+7+8+9=?

100+90+80+70+60+50+40+30+20+10+1+2+3+4+5+6+7+8+9=595

tk mk

Tính :

A = 1 + 2 + 3 + 4 + 5 + 5 + 6 + 7 + 8 + 9 + 10

A = ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + ( 5 + 5 ) + 10

A =     10    +    10    +    10    +   10   +    10    +      10

A =  60

B = 10 + 20 + 30 + 40 + 50 + 50 + 60 + 70 + 80 + 90 + 100

B = ( 10 + 90 ) + ( 20 + 80 ) + ( 30 + 70 ) + ( 40 + 60 ) + ( 50 + 50 ) + 100

B =       100     +      100      +      100     +      100       +      100      +      100

B =  600

A=56

B=600

450 nha !

= 450

5995

5295

1/10 + 2/20 + 3/30 + 4/40 + 5/50 + 6/60 + 7/70 + 8/80 + 9/90
          = 1/10 + 1/10 + 1/10 +1/10 + 1/10 + 1/10 + 1/10 + 1/10 + 1/10
          = 1/10 x 9
          = 9/10
1 đúng nha, thks

thank nha ban 

mik kb di nha

Để mình giúp bạn nha !!

A) 55

B) 550

a)=55

b)550

kb với mk nha

\(\frac{1}{10}+\frac{2}{20}+\frac{3}{30}+\frac{4}{40}+\frac{5}{50}+\frac{6}{60}+\frac{7}{70}+\frac{8}{80}+\frac{9}{90}\)

\(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}\)

\(=\frac{9}{10}\)

1/10=1/10 ; 2/20=1/10 .......9/90=1/10

1/10*10 =10/10=1

`1/10+2/20+3/30+4/40+5/50+6/60+7/70+8/80+9/90`

`=1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10+1/10`

`=1/10xx9`

`=9/10`

giúp mình bài này nha