( 8/14 + 6/14 ) + ( 5/12 - 1/12 + 8/12 )

= 1 + ( 4/12 + 8/12 )

= 1 + 1 = 2

=(8/14+6/14 )+(5/12+8/12-1/12)

=1+1

=2

\(\frac{8}{14}+\frac{5}{12}+\frac{6}{14}+\frac{8}{12}-\frac{1}{12}\)

\(=\left(\frac{8}{14}+\frac{6}{14}\right)+\left(\frac{5}{12}+\frac{8}{12}-\frac{1}{12}\right)\)

\(=1+1\)

\(=2\)

\(\frac{8}{14}+\frac{5}{12}+\frac{6}{14}+\frac{8}{12}-\frac{1}{12}\)

\(=\)\(\left(\frac{8}{14}+\frac{6}{14}\right)+\left(\frac{5}{12}+\frac{8}{12}-\frac{1}{12}\right)\)

\(=\)\(1+1\)

\(=\)\(2\)

\(\frac{8}{14}\) \(+\) \(\frac{5}{12}\) \(+\) \(\frac{6}{14}\) \(+\) \(\frac{8}{12}\) \(-\) \(\frac{1}{12}\)

=   (  \(\frac{8}{14}\) \(+\) \(\frac{6}{14}\))    \(+\)(  \(\frac{5}{12}\) \(+\) \(\frac{8}{12}\) \(-\) \(\frac{1}{12}\))

=               \(1\)                    \(+\)                       \(1\)

=                           \(2\)

- Hok T - 

mk tưởng bn học lớp 1

kg có cậu trả lời đi

not, mk lười lắm :)

( 6 x 8 – 48) : ( 10 + 11 + 12 + 13 + 14 + 15 )

= (48 – 48) : ( 10 + 11 + 12 + 13 + 14 + 15 )

= 0 : ( 10 + 11 + 12 + 13 + 14 + 15 )

= 0

câu trả lời là 0

Dh8s 8djr8xnikjtzndirnjxoxhtkfonycnfjdukdfmmg

Bdirnmfmfnhxhmffkxikdmfnfhxnzjdnyxjdm

Vsmdmdj

a.      ( 6 x 8 – 48 ) : ( 10 + 11 + 12 + 13 + 14 + 15 )

= (48 – 48) : ( 10 + 11 + 12 + 13 + 14 + 15 )

= 0 : ( 10 + 11 + 12 + 13 + 14 + 15 )

= 0

30x25x7x8

=(30x7)x(25x8)

=210x200

=42000

75x8x12x14

=(75x12)x(8x14)

=900x112

=100800

A) =(30*7)*(25*8)

=210*200

=4200 

B)=(75*8)*(12*14)

=600*168
=100800

a) 16 x 8 + 12 x 6    

= 4 x 4 x 8 + 4 x 3 x 6

= 4 x 32 + 4 x 18

= 4 x ( 32 + 18 )

= 4 x 50

= 200             

b) 16 x 7 + 14 x 2        

= 8 x 2 x 7 + 14 x 2

= 8 x 14 + 14 x 2

= ( 8 + 2 ) x 14

= 10 x 14

= 140

c) 8 x 12 - 96

= 8 x 12 - 12 x 8

= 0

a / 16 x 8 + 12 x 6

= ( 8 x 2 ) x ( 8 x 1 ) + ( 6 x 2 ) x ( 6x1 )

= 8 x ( 2 x 1 )     + 6 x ( 2 x 1 )

= 8 x 2 + 6 x 2

= 2 x ( 8 + 6 )

= 2 x 14

= 28

b / 16 x 7 + 14 x 2

= 16 x 7 + ( 7 x 2 ) x2

= 16 x 7 + 7 x 2 x 2

= 7 x ( 16 + 2 ) x 2

= 7 x 18 x2

= 7 x ( 6 x 3 ) x2

= 7 x6 x3 x2

= 7 x 6 x ( 3 x 2 )

= 7 x 6 x6 

= ( 7 x 6 ) x ( 6 x 1 )

= 6 x ( 7 x 1 )

= 6 x 7

= 42

c / 8 x 12 - 96

= ( 8 x 12 ) - 96

= 96 - 96

= 0

tớ k chắc cho lắm

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20

=(1+19)+(2+18)+(3+17)+(4+16)+(5+15)+(6+14)+(7+13)+(8+12)+(9+11)+20+10

=20+20+20+20+20+20+20+20+20+20+10

=20×10+10

=200+10

=210

= ( 1 + 19 ) + ( 2 + 18 ) + ( 3 + 17 ) + (4 + 16 ) + ( 5 + 15 ) + ( 6 + 14 ) + ( 7 + 13 ) + ( 8 + 12) + ( 9+ 11 ) + 20

= 20 + 20 + 20 +20 +  20 +20 + 20 + 20 + 20 +20

= 20 x 10

= 200

tui đầu tiên đó 

Ta có : \(1+2+3+...+19+20\)

          \(=\frac{\left(20+1\right).20}{2}=\frac{21.20}{2}=210\)

(19+1)+(18+2)+(17+3)+(16+4)+(15+5)+(14+6)+(13+7)+(12+8)+(11+9)+20)+10

=20+20+20+20+20+20+20+20+20+20=(20*10)+10

=210

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20

=(1+19)+(2+18)+(3+17)+(4+16)+(5+15)+(6+14)+(7+13)+(8+12)+(9+11)+(10+20)

=20+20+20+20+20+20+20+20+20+30

=(20 x 9) + 30

=180 + 30

=210

tk nha

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20

= (1+19)+(2+18)+(3+17)+(4+16)+(5+15)+(6+14)+(7+13)+(8+12)+(9+11)+20+10

= 20     +   20   +  20     +  20    +  20      +  20    +  20     +  20    +  20     +  20 + 10

= 10 . 10 +10 

=  100     +  10 = 110