a) Ta có: \(\dfrac{-5}{7}\left(\dfrac{14}{5}-\dfrac{7}{10}\right):\left|-\dfrac{2}{3}\right|-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)+\dfrac{10}{3}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)

\(=\dfrac{-5}{7}\cdot\dfrac{3}{2}\cdot\dfrac{21}{10}-\dfrac{3}{4}\cdot\dfrac{56}{3}+\dfrac{10}{3}\cdot\dfrac{8}{15}\)

\(=\dfrac{-9}{4}-14+\dfrac{16}{9}\)

\(=\dfrac{-1621}{126}\)

b) Ta có: \(\dfrac{17}{-26}\cdot\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)

\(=\dfrac{-17}{26}\cdot\dfrac{13}{17}\cdot\dfrac{-3}{2}-\dfrac{20}{3}\cdot\dfrac{3}{20}+\dfrac{2}{3}\cdot\dfrac{-33}{10}\)

\(=\dfrac{3}{4}-1-\dfrac{11}{5}\)

\(=-\dfrac{49}{20}\)

a2/4x4/7= 2/7                          b 10/21:5/7=2/3                               c10/21:2/3=5/7                                 d1/5x1/3=1/15           

e1/15:1/5=1/3                          g 1/15:1/5= 1/3                                h 1/15:1/3= 105     

k mình nhé bạn

đm ngu.tao bảo đầy đủ phép tính cơ con phương anh

a: \(\dfrac{18}{24}+\dfrac{35}{-21}-\dfrac{1}{2}\)

\(=\dfrac{3}{4}-\dfrac{5}{3}-\dfrac{1}{2}\)

\(=\dfrac{9-20-6}{12}=\dfrac{-17}{12}\)

b: \(\dfrac{-2}{3}-\dfrac{3}{-4}+\dfrac{5}{-6}\)

\(=-\dfrac{2}{3}+\dfrac{3}{4}-\dfrac{5}{6}\)

\(=\dfrac{-8+9-10}{12}=\dfrac{-9}{12}=\dfrac{-3}{4}\)

c: \(\left(\dfrac{3}{4}+\dfrac{-7}{2}\right)\cdot\left(\dfrac{10}{11}+\dfrac{2}{22}\right)\)

\(=\left(\dfrac{3}{4}-\dfrac{14}{4}\right)\cdot\left(\dfrac{10}{11}+\dfrac{1}{11}\right)\)

\(=-\dfrac{11}{4}\cdot1=-\dfrac{11}{4}\)

d: \(\left(\dfrac{7}{3}-\dfrac{-7}{2}\right):\left(-\dfrac{25}{6}\cdot\dfrac{1}{5}\right)\)

\(=\left(\dfrac{7}{3}+\dfrac{7}{2}\right):\dfrac{-5}{6}\)

\(=\dfrac{35}{6}\cdot\dfrac{6}{-5}=\dfrac{35}{-5}=-7\)

a) \(\dfrac{18}{24}+\dfrac{35}{-21}-\dfrac{1}{2}\)

\(=\dfrac{3}{4}-\dfrac{5}{3}-\dfrac{1}{2}\)

\(=\dfrac{9}{12}-\dfrac{20}{12}-\dfrac{6}{12}\)

\(=\dfrac{-17}{12}\)

b) \(\dfrac{-2}{3}-\dfrac{3}{-4}+\dfrac{5}{-6}\)

\(=\dfrac{-8}{12}+\dfrac{9}{12}-\dfrac{10}{12}\)

\(=\dfrac{-9}{12}\)

\(=\dfrac{-3}{4}\)

c) \(\left(\dfrac{3}{4}+\dfrac{-7}{2}\right).\left(\dfrac{10}{11}+\dfrac{2}{22}\right)\)

\(=\dfrac{-11}{4}.1\)

\(=\dfrac{-11}{4}\)

d) \(\left(\dfrac{7}{3}-\dfrac{-7}{2}\right):\left(-\dfrac{25}{6}.\dfrac{1}{5}\right)\)

\(=\dfrac{35}{6}:\dfrac{-5}{6}\)

\(=-7\)

b) Ta có: \(5^{x+4}-3\cdot5^{x+3}=2\cdot5^{11}\)

\(\Leftrightarrow2\cdot5^{x+3}=2\cdot5^{11}\)

\(\Leftrightarrow x+3=11\)

hay x=8

c) Ta có: \(2\cdot3^{x+2}+4\cdot3^{x+1}=10\cdot3^6\)

\(\Leftrightarrow18\cdot3^x+12\cdot3^x=10\cdot3^6\)

\(\Leftrightarrow30\cdot3^x=30\cdot3^5\)

Suy ra: x=5

d) Ta có: \(6\cdot8^{x-1}+8^{x+1}=6\cdot8^{19}+8^{21}\)

\(\Leftrightarrow6\cdot\dfrac{8^x}{8}+8^x\cdot8=6\cdot8^{19}+64\cdot8^{19}\)

\(\Leftrightarrow8^x\cdot\dfrac{35}{4}=70\cdot8^{19}\)

\(\Leftrightarrow8^x=8^{20}\)

Suy ra: x=20

a: =-1/3+1/3=0

b: \(=\dfrac{4}{11}\left(-\dfrac{2}{7}-\dfrac{4}{7}-\dfrac{1}{7}\right)=\dfrac{4}{11}\cdot\left(-1\right)=-\dfrac{4}{11}\)

c: \(=10+\dfrac{5}{9}-3-\dfrac{5}{7}-4-\dfrac{5}{9}=3-\dfrac{5}{7}=\dfrac{16}{7}\)

d: \(=\dfrac{1}{3}+\dfrac{7}{4}-\dfrac{7}{4}+\dfrac{4}{5}=\dfrac{1}{3}+\dfrac{4}{5}=\dfrac{5+12}{15}=\dfrac{17}{15}\)

a: =-1/3+1/3=0

b: =10+59−3−57−4−59=3−57=167=10+59−3−57−4−59=3−57=167

d: 

12+3/7-11+3/7 tính bằng cách thuận tiện nhé

Ta có:

Tập hợp A:
\(A=\left\{1;5;9;13;17;21;25\right\}\)

Tập hợp B:

\(B=\left\{0;1;3;5;10;13\right\}\)

Mà: \(A\cap B\)

\(\Rightarrow A\cap B=\left\{1;5;13\right\}\)

⇒ Chọn B

a: \(C=\dfrac{-1}{2}:\dfrac{-2}{3}:\dfrac{-3}{4}\)

\(=\dfrac{-1}{2}\cdot\dfrac{3}{-2}\cdot\dfrac{4}{-3}\)

\(=-\dfrac{4}{4}=-1\)

b: \(D=\dfrac{-6}{5}:\dfrac{-5}{4}:\dfrac{-4}{3}\)

\(=-\dfrac{6}{5}\cdot\dfrac{4}{5}\cdot\dfrac{3}{4}\)

\(=\dfrac{-18}{25}\)

c: \(\dfrac{4}{20}+\dfrac{16}{42}+\dfrac{6}{15}+\dfrac{-3}{5}+\dfrac{2}{21}+\dfrac{-10}{21}+\dfrac{3}{20}\)

\(=\left(\dfrac{4}{20}+\dfrac{-3}{5}+\dfrac{6}{15}\right)+\left(\dfrac{16}{42}+\dfrac{2}{21}-\dfrac{10}{21}\right)+\dfrac{3}{20}\)

\(=\left(\dfrac{1}{5}-\dfrac{3}{5}+\dfrac{2}{5}\right)+\left(\dfrac{8}{21}+\dfrac{2}{21}-\dfrac{10}{21}\right)+\dfrac{3}{20}\)

\(=\dfrac{3}{20}\)

d: \(\dfrac{42}{46}+\dfrac{250}{186}+\dfrac{-2121}{2323}+\dfrac{-125125}{143143}\)

\(=\dfrac{21}{23}+\dfrac{125}{93}+\dfrac{-21}{21}+\dfrac{-125}{143}\)

\(=\dfrac{125}{93}-\dfrac{125}{143}=\dfrac{6250}{13299}\)

a)(-0,25).4/17.(-3 5/21).(-7/12)

= -1/17 . (-68/21) . ( -7/21)

= -4/63

b) (-2/5).4/15+(-3/10).4/15

= 4/15. [-2/5 + (-3/10)]

= 4/15 . (-7/10)

= -14/75

c)21-3 3/4:(3/8-1/6)

= 21 - 15/4 : 5/24

= 21 - 18

= 3

d) (-3/4+2/5):3/7+(3/5+-1/4):3/7

= [(-3/4 + 2/5) + (3/5 + -1/4)] : 3/7

= [-7/20 + (-17/20)] : 3/7

= -6/5 : 3/7

= -14/5

C = 1/1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5

C = 1/1 - 1/5

C = 4/5