12+12+12+13+13+13+2222+2222+3^4=4600

4600 nha chị/anh

=12/13x(1/4+1/6+1/8)

=12/13x13/24

=12/24

=1/2

a/16

b/15

tui tick cậu rùi c5u tick tui nha

a) 16   

b)15

Nguyễn Hương Giang tự hỏi tự trả lời!!!

1/4 x 12/13 + 1/6 x 12/13 + 1/8 x 12/13

= 12/13 x (1/4 + 1/6 + 1/8 )

= 12/13 x 13/14

= 1/2

1/4 x 12/13 + 1/6 x 12/13 + 1/8 x 12/13= 0.5

hok tốt

12/13x(1/4+1/6+1/8)=12/13x13/24=12/24=1/2

gợi ý

1+12=13

ghép hai số liên tiép với nhau có ra 7 cặp

A=13+13.(12+1)+...+13.(12^12+1)

=61

k mk

câu này đi

12 + 12 + 13 + 13 + 11

=61

12+12+13+13+11=61

9/13 x 7/12 + 9/13 x 5/12 - 9/13

= 9/13 x (7/12 + 5/12 - 1)

= 9/13 x 0

= 0

4/13 x 5/12 + 4/13 x 7/12 - 4/3

= 4/13 x (5/12 + 7/12) - 4/3

= 4/13 x 1 - 4/3

= 4/13 - 4/3

= -40/39

a) 9/13 x 7/12 + 9/13 x 5/12 - 9/13

= 9/13 x ( 5/12 + 7/12 - 1 )

= 9/13 x 0

= 0

b) 4/13 x 5/12 + 4/13 x 7/ 12 - 4/3

= 4/13 x ( 5/12 + 7/12 - 13/3 )

= 4/13 x ( - 10/3 )

= -40/39 

a) \(\frac{9}{13}\cdot\frac{7}{12}+\frac{9}{13}\cdot\frac{5}{12}-\frac{9}{13}\)

\(=\frac{9}{13}.\left(\frac{7}{12}+\frac{5}{12}-1\right)=\frac{9}{13}.\left(1-1\right)=\frac{9}{13}.0=0\)

b) \(\frac{4}{13}\cdot\frac{5}{12}+\frac{4}{13}\cdot\frac{7}{12}-\frac{4}{3}\)

\(=\frac{4}{13}.\left(\frac{5}{12}+\frac{7}{12}\right)-\frac{4}{3}=\frac{4}{13}.1-\frac{4}{3}=\frac{4}{13}-\frac{4}{3}\)