\(\left(-\dfrac{1}{2}\right)^2\div\dfrac{1}{4}-2\times\left(-\dfrac{1}{2}\right)^2\\= \dfrac{1}{4}\div\dfrac{1}{4}-2\times\dfrac{1}{4}\\ =1-\dfrac{1}{2}\\ =\dfrac{1}{2}\)

\(\left(-2\right)^3\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right)\div\dfrac{5}{12}\)

=  \(-6\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-\dfrac{11}{6}\right)\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{1}{2}\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{6}{5}\)

=  \(\dfrac{1}{4}-\dfrac{6}{5}\)

=  \(-\dfrac{19}{20}\)

\(\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\\ =\dfrac{58}{9}+\dfrac{7}{11}-\dfrac{40}{9}+\dfrac{26}{11}\\ =\dfrac{58}{9}-\dfrac{40}{9}+\dfrac{7}{11}+\dfrac{26}{11}\\ =12+3\\ =15\)

\(a,\left(\dfrac{-1}{2}\right)^2:\dfrac{1}{4}-2\left(-\dfrac{1}{2}\right)^2\)

\(=\left(-\dfrac{1}{2}\right)^2\left(4-2\right)\)

\(=\dfrac{1}{4}.2=\dfrac{1}{2}\)

\(b,\left(-2\right)^3.\dfrac{-1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right):\dfrac{5}{12}\)

\(=\left(-8\right).\dfrac{-1}{24}+\left(-\dfrac{1}{2}\right).\dfrac{12}{5}\)

\(=\dfrac{1}{3}+\left(-\dfrac{1}{5}\right)=\dfrac{2}{15}\)

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

\(=\dfrac{701}{99}-\dfrac{206}{99}=\dfrac{495}{99}=5\)

\(d,10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+\dfrac{3}{15\%}\)

\(=\dfrac{51}{5}-30+20=\dfrac{1}{5}\)

\(e,\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)

\(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\left(-\dfrac{7}{11}\right)\)

\(=-\dfrac{5}{11}\)

\(f,\dfrac{-5}{7}.\dfrac{2}{11}+\left(-\dfrac{5}{7}\right).\dfrac{9}{11}+1\dfrac{5}{7}\)

\(=\left(-\dfrac{5}{7}\right)\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\)

\(=\left(-\dfrac{5}{7}\right)+\dfrac{12}{7}=1\)

\(10\dfrac{1}{5}-5\dfrac{1}{2}\times\dfrac{60}{11}+3\div15\%\\ =\dfrac{51}{5}-\dfrac{11}{2}\times\dfrac{60}{11}+3\div\dfrac{15}{100}\\ =\dfrac{51}{5}-30+20\\ =10,2-30+20\\ =0,2\)

\(\dfrac{5}{7}\times\dfrac{5}{11}+\dfrac{5}{7}\times\dfrac{2}{11}-\dfrac{5}{7}\times\dfrac{14}{11}\\ =\dfrac{5}{7}\times\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)\\ =\dfrac{5}{7}\times-\dfrac{7}{11}=-\dfrac{5}{11}\)

\(-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+1\dfrac{5}{7}\\ =-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times1+\dfrac{12}{7}\\ =1\)

a) \(\frac{8}{40}+\frac{-14}{35}-\frac{12}{60}\)

= \(\frac{1}{5}-\frac{2}{5}-\frac{1}{5}\)

= \(\left(\frac{1}{5}-\frac{1}{5}\right)-\frac{2}{5}\)

= \(-\frac{2}{5}\)

b) 5/7.5/11 + 5/7.5/11 - 5/7.14/11

= 5/7.(5/11 + 5/11 - 14/11) 

= 5/7.(-4/11)

= -20/77

c) \(19\frac{5}{8}:\frac{7}{12}-15\frac{1}{4}:\frac{7}{12}\)

= \(\left(19\frac{5}{8}-15\frac{1}{4}\right):\frac{7}{12}\)

=  \(\frac{35}{8}:\frac{7}{12}\)

=  \(\frac{15}{2}\)

d) 2/5.1/3 - 2/15 : 1/5 + 3/5.1/3

= (2/5 + 3/5).1/3 - 2/15 . 5

= 1.1/3 - 2/3

= 1/3 - 2/3

= -1/3

e) \(\frac{4}{9}.19\frac{1}{3}-\frac{4}{9}.39\frac{1}{3}\)

= \(\frac{4}{9}.\left(19\frac{1}{3}-39\frac{1}{3}\right)\)

= \(\frac{4}{9}.\left(-20\right)\)

= \(\frac{-80}{9}\)

g) \(\frac{81.17-15.81}{81.17-81.15}\)

= 1

a)8/40+-14/35-12/60=1/5+(-2/5)-1/5=-2/5

b)5/7.5/11+5/7.5/11-5/7.14/11=5/7.(5/11+5/11-14/11)=5/7.-4/11=-20/77

c)19 5/8:7/12-15 1/4:7/12=(19 5/8-15 1/4):7/12=35/8.12/7=15/2

d)2/5.1/3-2/15:1/5+3/5.1/3=2/15-2/15.5/1+3/15=2/15.2/3+1/5=-5/15=-1/5

e)4/9.19 1/3-4/9.39 1/3=4/9.(19 1/3- 39 1/3)=4/9. 20=80/9

g)81.17-15.81/81.17-81.15=81.(17-15)-15.1.17=81.2-255=162-255=-90

Chúc bạn học giỏi!!! hihi

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: Dấu hiệu là thời gian giải bài

Số các giá trị là 10

b: 

Mốt là 7 và 8

c: Phần lớn làm xong trong 7 hoặc 8 phút

ai giúp mình sẽ kb với k

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

Xóa nhanh đi ko CTV xóa giờ

Chia chúng nó ra

Câu dễ vậy bạn cần hỏi

a) 3/2 x 4/7 = 6/7

​8/21 : 2/3= 4/7

​8/21 : 4/7 = 2/3

4/7 x 2/3 = 8/21

​b) 3/11 x 2 = 6/11

​6/11: 3/11 = 2

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