\(\left(\frac{12}{26}+\frac{5}{8}\right)+\frac{7}{13}=\frac{13}{8}\) 

mk đầu tiên bạn nhé

(12/26+5/8)+7/13

=(12/26+7/13)+5/8

=1+5/8=8/8+5/8=13/8

6/13 + 5/8 + 7/13

= 6/13 + 7/13 + 5/8

= 1 + 5/8 = 1/5/8 

(12/26+5/8)+7/13

1+5/8 =13/8

Ai ủng hộ cho cái Li-Ke đi mà

5 + 7 = 12

6 + 8 = 26

7 + 9 = 42 

8 + 10 = 60

Không bieetscos đúng không . Hu hu

8+10=18

k nha

8 + 10 = 80

=6/13+7/13+5/8=1+5/8=13/8

a. bằng77

b. bằng 13

lớp 2 đã học cái này rồi à

a. bằng77

b. bằng 13

a: =(8/27+19/27)+(4/15+11/15)=1+1=2

b: =(12/13+8/13+6/13)+(2/7+5/7)=2+1=3

=\(\frac{5x6x26}{12x13x25}=\frac{780}{3900}=\frac{1}{5}\)

\(\frac{5}{12}\times\frac{6}{13}\times\frac{26}{25}=\frac{5\times6\times26}{12\times13\times25}=\frac{780}{3900}=\frac{1}{5}\)

\(=\frac{5\cdot6\cdot26}{12\cdot13\cdot25}\)

\(=\frac{2}{20}\)

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

a, \(\frac{12\times3\times4}{24\times25\times26}\)=\(\frac{12\times3\times2\times2}{12\times2\times25\times13\times2}\)=\(\frac{1\times3\times1\times1}{1\times1\times25\times13\times1}\)=\(\frac{3}{25\times13}\)=\(\frac{3}{325}\)

b, \(\frac{5}{8}\)\(\times\)\(\frac{3}{7}\)\(+\)\(\frac{5}{8}\)\(\times\)\(\frac{4}{7}\)= \(\frac{5}{8}\)\(\times\)\((\)\(\frac{3}{7}\)\(+\)\(\frac{4}{7}\)\()\)

                                                                       = \(\frac{5}{8}\)\(\times\)\(1\)=\(\frac{5}{8}\)

thanks

a) \(\frac{12.3.4}{24.25.26}=\frac{3.2.2.3.4}{2.3.4.25.2.13}=\frac{3}{13.25}\)(Hình như đề có gì sai sai)

b) \(\frac{5}{8}.\frac{3}{7}+\frac{5}{8}.\frac{4}{7}=\frac{5}{8}\left(\frac{3}{7}+\frac{4}{7}\right)=\frac{5}{8}.1=\frac{5}{8}\)

1+2-3-4+5+6-7-8+9+................+33

=1+(2-3-4+5)+(6-7-8+9)+............+(30-31-32+33)

=1+0+0+..............+0

=1

Cảm ơn nha ! Kết bạn với tớ nhé!

1+2-3-3+5+6-7-8+9+10-11-12+13+...............+33

= 1 + ( 2-3-4+5)+(6-7-8+9)+......+(30-31-32+33)

=1