`a, 2/7 +(3/7 + 5/7)= 2/7 + 3/7 + 5/7=(2/7 +5/7)+3/7= 1+3/7=7/7+3/7=10/7`

`b, (6/11+5/11)+4/11= 11/11+4/11=15/11`

`c, (5/6 + 7/6)+2/6= 12/6 + 2/6= 14/6= 7/3`

`@ yl`

\(a\) \(\dfrac{2}{7}+\left(\dfrac{3}{7}+\dfrac{5}{7}\right)=\dfrac{2}{7}+\dfrac{8}{7}=\dfrac{10}{7}\)

\(b\) \(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)+\dfrac{4}{11}=\dfrac{11}{11}+\dfrac{4}{11}=\dfrac{15}{11}\)

\(c\) \(\left(\dfrac{5}{6}+\dfrac{7}{6}\right)+\dfrac{2}{6}=\dfrac{12}{6}+\dfrac{2}{6}=\dfrac{14}{6}=\dfrac{7}{3}\)

Bn ghi đề vào nhé .

mik tick cho

3/11 x 2 = 6/11

6/11 : 3/11 = 2

6/11 : 2 = 3/11

2/3 x 11 = 22/3

4/2 x 7 = 14

8/7 : 2/7 = 4

8/7 : 4 = 2/7

2/7 x 4 = 8/7

L: \(\dfrac{7}{6}\) +\(\dfrac{8}{6}\) = \(\dfrac{15}{6}\)

T: \(\dfrac{1}{11}\) + \(\dfrac{7}{11}\) + \(\dfrac{9}{11}\) = \(\dfrac{17}{11}\)

Ạ: \(\dfrac{4}{11}\) + \(\dfrac{2}{11}\) = \(\dfrac{6}{11}\)

Đ: \(\dfrac{3}{6}\) + \(\dfrac{1}{6}\) + \(\dfrac{7}{6}\) = \(\dfrac{11}{6}\)

À: \(\dfrac{3}{11}\) + \(\dfrac{9}{11}\) = \(\dfrac{12}{11}\)

ĐÀ LẠT

Xóa nhanh đi ko CTV xóa giờ

Chia chúng nó ra

Câu dễ vậy bạn cần hỏi

a: =11/11x3/7=3/7

b: =2/7x5/2=5/7

\(a,\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}=\dfrac{11}{11}\times\dfrac{3}{7}=1\times\dfrac{3}{7}=\dfrac{3}{7}\\ b,\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}=\dfrac{2}{7}\times\dfrac{5}{2}=\dfrac{5}{7}\)

a 11/11x3/7=3/7

b 2/7x5/2=5/7

4) \(\left(\dfrac{3}{7}\right)^2\cdot\left(-7\right)^4\)

\(=\left(\dfrac{3}{7}\right)^2\cdot\left[\left(-7\right)^2\right]^2\)

\(=\left(\dfrac{3}{7}\right)^2\cdot49^2\)

\(=\left(\dfrac{3}{7}\cdot49\right)^2\)

\(=\left(\dfrac{147}{7}\right)^2\)

\(=21^2\)

\(=441\)

5) \(\left(-11\right)^{12}\cdot\left(\dfrac{4}{11}\right)^6\)

\(=\left[\left(-11\right)^2\right]^6\cdot\left(\dfrac{4}{11}\right)^6\)

\(=121^6\cdot\left(\dfrac{4}{11}\right)^6\)

\(=\left(121\cdot\dfrac{4}{11}\right)^6\)

\(=44^6\)

6) \(6^8\cdot\left(\dfrac{5}{7}\right)^7\)

\(=6^8\cdot\dfrac{5^7}{6^7}\)

\(=\dfrac{6^8\cdot5^7}{6^7}\)

\(=6\cdot5^7\)

\(=469750\)

\(\left(\dfrac{3}{7}\right)^2\cdot\left(-7\right)^4=\dfrac{9}{49}\cdot49^2=9\cdot49=441\)

\(\left(-11\right)^{12}\cdot\left(\dfrac{4}{11}\right)^4=11^{12}\cdot\dfrac{4^4}{11^4}=11^8\cdot4^4=54875873536\) 

\(\left(-6\right)^8\cdot\left(\dfrac{5}{6}\right)^7=6^8\cdot\dfrac{5^7}{6^7}=6\cdot5^7=469750\)

\(A=\frac{4}{3.7}+\frac{4}{7.11}+...+\frac{4}{107.111}\)

\(A=\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+...+\frac{1}{107}-\frac{1}{111}\)

\(A=\frac{1}{3}-\frac{1}{111}\)

\(A=\frac{12}{37}\)

mà dài quá bạn ơi ban tách ra thành nhiều câu hỏi đi thế này trả lời lâu lắm

a, = \(\dfrac{3}{4}\)x\(\dfrac{41}{24}\) = \(\dfrac{41}{32}\)

b, = \(\dfrac{1}{11}\) : \(\dfrac{1}{42}\) - \(\dfrac{20}{11}\) = \(\dfrac{42}{11}\) - \(\dfrac{20}{11}\) = \(\dfrac{22}{11}\) = 2

c, = \(\dfrac{26}{7}\) x 3 : \(\dfrac{1}{3}\) = \(\dfrac{78}{7}\) : \(\dfrac{1}{3}\) = \(\dfrac{234}{7}\)

Học tốt nhá

 Cảm ơn nhiều ạ

`a)1/7xx2/7+1/7xx5/7+6/7`

`=1/7xx(2/7+5/7)+6/7`

`=1/7xx1+6/7`

`=1/7+6/7=1`

`b)6/11xx4/9+6/11xx7/9-6/11xx2/9`

`=6/11xx(4/9+7/9-2/9)`

`=6/11xx9/9`

`=6/11`

Sorry nãy ghi thiếu.

`c)4/25xx5/8xx25/4xx24`

`=(4xx5xx25xx24)/(25xx8xx4)`

`=(4xx5xx24)/(4xx8)`

`=(5xx24)/8`

`=5xx3=15`

a, \(\dfrac{1}{7}.\dfrac{2}{7}+\dfrac{1}{7}.\dfrac{5}{7}+\dfrac{6}{7}\)

\(=\dfrac{1}{7}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{6}{7}\)
\(=\dfrac{1}{7}.1+\dfrac{6}{7}\)

\(=\dfrac{1}{7}+\dfrac{6}{7}=1\)

b, \(\dfrac{6}{11}.\dfrac{4}{9}+\dfrac{6}{11}.\dfrac{7}{9}-\dfrac{6}{11}.\dfrac{2}{9}\)

\(=\dfrac{6}{11}.\left(\dfrac{4}{9}+\dfrac{7}{9}-\dfrac{2}{9}\right)\)

\(=\dfrac{6}{11}.1=\dfrac{6}{11}\)

c, \(\dfrac{4}{25}.\dfrac{5}{8}.\dfrac{25}{4}.24\)

\(=\left(\dfrac{4}{25}.\dfrac{25}{4}\right).\left(\dfrac{5}{8}.24\right)\)

\(=1.15=15\)