bang 84 cau nhe.

1+2+3+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9

=(1+2+3+4=5=6=7+8+9)x2

=45x2

=90 

Chúc bạn học giỏi nha!!!

1+2+3+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9=90

bài này không có kết quả nha

=45+0-1-2-3-4-5-6-7-8-9

=45-1-2-3-4-5-6-7-8-9

=-55

Tk nha.Chúc bn năm mới vui vẻ!Happy new year

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45

1+1+1+1+1=...?

2+2+2+2+2=...?

3+3+3+3+3=...?

4+4+4+4+4=4x5=20

5+5+5+5+5=5x5=25

6+6+6+6+6=6x5=30

7+7+7+7+7=7x5=35

8+8+8+8+8=8x5=40

9+9+9+9+9=9x5=45

1+1+1+1+1=5

2+2+2+2+2=10

3+3+3+3+3=15

4+4+4+4+4=20

5+5+5+5+5=25

6+6+6+6+6=30

7+7+7+7+7=35

8+8+8+8+8=40

9+9+9+9+9=45

\(\dfrac{2}{5}+\dfrac{1}{4}=\dfrac{8}{20}+\dfrac{5}{20}=\dfrac{13}{20}\)
\(\dfrac{1}{3}+\dfrac{3}{5}=\dfrac{5}{15}+\dfrac{9}{15}=\dfrac{14}{15}\)
\(\dfrac{1}{2}+\dfrac{1}{4}=\dfrac{2}{4}+\dfrac{1}{4}=\dfrac{3}{4}\)
\(\dfrac{1}{8}+\dfrac{5}{6}=\dfrac{3}{24}+\dfrac{20}{24}=\dfrac{23}{24}\)

ĐÂSDWADAS

a. 10 – 9 + 8 – 7 + 6 – 5 + 4 – 3 + 2 – 1

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

= 1 + 1 + 1 + 1 + 1

= 5

b. 1 + 3 + 5 + 7 + 9 + 10 + 8 + 6 + 4 + 2 + 0

= (0 +10) +(1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) + 5

= 10 + 10 + 10 + 10 + 10 + 5

= 55

a) 10 - 9 + 8 - 7 + 6 - 5 + 4 - 3 + 2 - 1

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

= 1 + 1 + 1 + 1 + 1

= 1 x 5

= 5

b) 1 + 3 + 5 + 7 + 9 + 10 + 8 + 6 + 4 + 2 + 0

= 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10

= (0 + 10) x 11 : 2

= 10 x 11 : 2

= 5 x 11

= 55

a)5

b)55

chúc bạn học tốt

9 nha ban

ung ho nha

1+4-2+5-3+6-9+6-5+4-7+8-3+5-1=9

ủng hộ nha

1+4-2+5-3+6-9+6-5+4-7+8-3+5-1= 9

a) 1/2

b) 3/8

~~~~~~~~~hok tốt~~~~~~~~~~~~

A/ \(\frac{1}{2}\)

B/ \(\frac{3}{8}\)  

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tk nha bn

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?!

:))

Spam ko zui đâu cj:)