a. \(\dfrac{656565}{272727}=\dfrac{65}{27}\)

b. \(\dfrac{2}{7}\left(\dfrac{3}{4}+\dfrac{9}{4}\right)=\dfrac{6}{7}\)

\(=\)\(\frac{1}{2}\)-\(\frac{-13}{6}\)-\(\frac{5}{6}\)

\(=\)\(\frac{3}{6}\)-\(\frac{-13}{6}\)-\(\frac{5}{6}\)

\(=\)\(\frac{11}{6}\)

\(\frac{3}{4}-0,25-\left(\frac{7}{3}+\frac{-9}{2}\right)-\frac{5}{6}\)

\(=\frac{3}{4}-\frac{1}{4}-\left(\frac{14}{6}+\frac{-27}{6}\right)-\frac{5}{6}\)

\(=\frac{1}{2}-\frac{-13}{6}-\frac{5}{6}\)

\(=\frac{3}{6}+\frac{13}{6}-\frac{5}{6}\)

\(=\frac{16}{6}-\frac{5}{6}\)

\(=\frac{11}{6}\)

\(a,\frac{1}{3}x+0.25=\frac{5}{7}\)

\(\Leftrightarrow\frac{1}{3}x=\frac{13}{28}\)

\(\Leftrightarrow x=\frac{39}{28}\)

vậy...

\(b,\frac{11}{12}x+0,25=\frac{5}{6}\)

\(\Leftrightarrow\frac{11}{12}x=\frac{7}{12}\)

\(\Leftrightarrow x=\frac{7}{11}\)

vậy.....

\(c,\left(\frac{-1}{3}\right)^2+\frac{2}{3}x=\frac{1}{4}\)

\(\Leftrightarrow\frac{1}{9}+\frac{2}{3}x=\frac{1}{4}\)

\(\Leftrightarrow\frac{2}{3}x=\frac{5}{36}\)

\(\Leftrightarrow x=\frac{5}{24}\)

vậy......

\(d,\left(3x+2\right)^3=-\frac{8}{125}\)

\(\Leftrightarrow3x+2=-\frac{2}{5}\)

\(\Leftrightarrow3x=-\frac{12}{5}\)

\(\Leftrightarrow x=-\frac{4}{5}\)

vậy.......

\(\frac{1}{3x}+0,25=\frac{5}{7}\)

\(\frac{1}{3x}+\frac{1}{4}=\frac{5}{7}\)

\(\frac{1}{3x}=\frac{13}{28}\)

\(3x=\frac{28}{13}\)

\(x=\frac{28}{39}\)

\(\frac{11}{12x}+0,25=\frac{5}{6}\)

\(\frac{11}{12x}+\frac{1}{4}=\frac{5}{6}\)

\(\frac{11}{12x}=\frac{7}{12}\)

\(x=\frac{11}{12}:\frac{7}{12}\)

\(x=\frac{7}{11}\)

\(\left(-\frac{1}{3}\right)^2+\frac{2}{3x}=\frac{1}{4}\)

\(\frac{1}{9}+\frac{2}{3x}=\frac{1}{4}\)

\(\frac{2}{3x}=\frac{5}{36}\)

\(x=\frac{2}{3}:\frac{5}{36}\)

\(x=\frac{5}{24}\)

\(\left(3x+2\right)^3=\left(-\frac{8}{125}\right)\)

\(\left(3x+2\right)^3=\left(-\frac{2}{5}\right)^3\)

\(\Rightarrow3x+2=-\frac{2}{3}\)

\(3x=-\frac{8}{3}\)

\(x=-\frac{9}{8}\)

**1/3x + 0.25= 5/7
1/3x= 5/7 - 0.25
1/3x= 13/28
x= 13/28: 1/3
x= 39/28

**11/12x+ 0.25= 5/6
11/12x= 5/6- 0.25
11/12x= 7/12
x= 7/12:11/12
x= 7/11
**(-1/3)^2+ 2/3x=1/4
1/9+ 2/3x= 1/4
2/3x= 1/4- 1/9

2/3x= 5/36
x= 5/35: 2/3
x= 5/24
**(3x+2)^3= -8/125

(3x+2)^3= -0.064
(3x+2)^3= -0.4^3
=> 3x+2= -0.4
3x= -0.4- 2
3x= -2.4
x= -2.4: 3
x= -0.8
x= -4/5 
!!!Mình giải all cho bạn rồi nhaa. Chúc bạn học tốt nhé!!!

(7/111 - 4/33 + 9/37).(1/2 - 1/3 -1/6)

= (7/111 - 4/33 + 9/37).0

= 0

(7/111 - 4/33 + 9/37).(1/2 - 1/3 - 1/6)

= (7/111 - 4/33 + 9/37).0

= 0

\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)

\(=-8.\left(\frac{3}{4}-\frac{1}{4}\right):\left(\frac{27}{12}-\frac{14}{12}\right)\)

\(=-8.\frac{1}{2}:\frac{13}{12}\)

\(=-\frac{8}{2}.\frac{13}{12}\)

\(=-\frac{8.13}{2.12}\)

\(=-\frac{2.4.13}{2.4.3}\)

\(=-\frac{13}{3}\)

^_^

\(D=\left(-2\right)^3x\left(\frac{3}{4}-0,25\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)

\(D=-8.\frac{1}{2}:\frac{13}{12}\)

\(D=-4:\frac{13}{12}\)

\(D=\frac{-48}{13}\)