b) \(\frac{3}{x-5}=\frac{-4}{x+2}\)

=> 3.(x + 2) = (x - 5). (-4)

= 3x + 6 = -4x + 20

= 3x - 4x = 26

=> -x = 26

=> x = -26

c) \(\frac{x}{-2}=\frac{-8}{x}\)

=> x.x = -2 . (-8)

 => x² = 16

=> x = 4

t i c k nha!!! 645646677778879078452352543546456457567564546567

còn câu a

|\(\frac32x\) + \(\frac12\)| = |4\(x\) - 1|

\(\left[\begin{array}{l}\frac32x+\frac12=-4x+1\\ \frac32x+\frac12=4x-1\end{array}\right.\)

\(\left[\begin{array}{l}\frac32x+4x=1-\frac12\\ \frac32x-4x=-1-\frac12\end{array}\right.\)

\(\left[\begin{array}{l}\frac{11}{2}x=\frac12\\ -\frac52x=-\frac32\end{array}\right.\)

\(\left[\begin{array}{l}x=\frac12:\frac{11}{2}\\ x=-\frac32:\frac{-5}{2}\end{array}\right.\)

\(\left[\begin{array}{l}x=\frac12\times\frac{2}{11}\\ x=-\frac32\times\frac{-2}{5}\end{array}\right.\)

\(\left[\begin{array}{l}x=\frac{1}{11}\\ x=\frac35\end{array}\right.\)

Vậy \(x\in\) {\(\frac{1}{11};\frac35\)}

|\(\frac54x\) - \(\frac72\)| - |\(\frac58x\) + \(\frac35\)| = 0

|\(\frac54x\) - \(\frac72\)| = |\(\frac58x\) + \(\frac35\)|

\(\left[\begin{array}{l}\frac54x-\frac72=-\frac58x-\frac35\\ \frac54x-\frac72=\frac58x+\frac35\end{array}\right.\)

\(\left[\begin{array}{l}\frac54x+\frac58x=\frac72-\frac35\\ \frac54x-\frac58x=\frac72+\frac35\end{array}\right.\)

\(\left[\begin{array}{l}\frac{15}{8}x=\frac{29}{20}\\ \frac58x=\frac{41}{10}\end{array}\right.\)

\(\left[\begin{array}{l}x=\frac{29}{10}:\frac{15}{8}\\ x=\frac{41}{10}:\frac58\end{array}\right.\)

\(\left[\begin{array}{l}x=\frac{116}{75}\\ x=\frac{164}{25}\end{array}\right.\)

Vậy \(x\in\) {\(\frac{116}{75}\); \(\frac{164}{25}\)}

a) \(\frac{9}{20}\)                                                   c) \(\frac{-55}{4}\)                                                                                                                                 

b) \(\frac{116}{75}\)                                                d) \(\frac{-76}{45}\)

đúng hết đấy nhé mình tính kĩ lắm ko sai đâu

       chúc may mắn

a)\(\left(\frac{3}{29}-\frac{1}{5}\right)\cdot\frac{29}{3}\)

\(=\left(\frac{3}{29}\cdot\frac{29}{3}\right)-\left(\frac{1}{5}\cdot\frac{29}{3}\right)\)

\(=1-\frac{29}{15}\)

\(=\frac{-14}{15}\)

b)\(\frac{16}{15}\cdot\frac{-5}{14}\cdot\frac{54}{24}\cdot\frac{56}{21}\)

=\(=\frac{16\cdot\left(-5\right)\cdot54\cdot56}{15\cdot14\cdot24\cdot21}\)

\(=\frac{2^4\cdot\left(-5\right)\cdot2\cdot3^3\cdot2^3\cdot7}{3\cdot5\cdot7\cdot2\cdot2^3\cdot3\cdot7}\)

\(=2^4\)

c)\(\frac{37}{7}\cdot\frac{8}{11}+\frac{37}{7}\cdot\frac{5}{11}-\frac{37}{7}\cdot\frac{2}{11}\)

\(=\frac{37}{7}\cdot\left(\frac{8}{11}+\frac{5}{11}-\frac{2}{11}\right)\)

\(=\frac{37}{7}\cdot1\)

\(=\frac{37}{7}\)

Đúng nhớ k nhen!

b)\(-2^4\)nãy mk nhầm

a) = 3/3 x ( -24/54 +45/54 ) : 7/12

   = 1 x 21/54 x 12/7

   = 18/27 

( hiện tại mik chỉ lm đc thế này thui. thông cảm nk )

S = \(\frac12\times\frac13\) + \(\frac13\times\frac14\) + \(\frac14\times\frac15\) + \(\frac15\times\frac16\) + \(\frac17\times\frac18\) + \(\frac18\times\frac19\)

S = \(\frac12\) - \(\frac13\) + \(\frac13\) - \(\frac14\) + \(\frac14\) - \(\frac15\) + \(\frac15\) - \(\frac16\) + \(\frac17\) - \(\frac18\) + \(\frac18\) - \(\frac19\)

S = \(\frac12\) - \(\frac19\)

S = \(\frac{9}{18}-\frac{2}{18}\)

S = \(\frac{7}{18}\)

\(\frac{3}{7}=\frac{y}{21}\Rightarrow y=\frac{3\times21}{7}=9\)

\(\frac{3}{x-5}=\frac{-4}{x+2}\)

\(\Leftrightarrow3.\left(x+2\right)=-4\left(x-5\right)\)

\(\Leftrightarrow3x+6=-4x+20\)

\(\Leftrightarrow3x+4x=20-6\)

\(\Leftrightarrow7x=14\)

\(\Leftrightarrow x=2\)

Cảm ơn

3/2-(43/8+X-75/24):50/3=1/2

3/2-(43/8+X-75/24)=25/3

43/8+X-75/24=-41/6

43/8+X=(-41/6)+75/24

43/8+X=(-85/24)

X=85/24-43/8

X=-109/12

Vậy X=-109/12

\(\frac{3}{2}-\left(5\frac{3}{8}+x-\frac{75}{24}\right):16\frac{2}{3}\)\(=\frac{1}{2}\)

            \(\left(5\frac{3}{8}+x-\frac{75}{24}\right):16\frac{2}{3}=\frac{3}{2}-\frac{1}{2}\)

            \(\left(5\frac{3}{8}+x-\frac{75}{24}\right):16\frac{2}{3}=1\)

             \(5\frac{3}{8}+x-\frac{75}{24}\)\(=1.16\frac{2}{3}\)

             \(5\frac{3}{8}+x-\frac{75}{24}=\frac{50}{3}\)

            \(5\frac{3}{8}+x=\frac{50}{3}+\frac{75}{24}\)

             \(5\frac{3}{8}+x=\frac{475}{24}\)

             \(x=\frac{475}{24}-5\frac{3}{8}\)

             \(x=\frac{173}{12}\)

\(1-\left(5\frac{3}{8}+x+7\frac{5}{24}\right):16\frac{2}{3}=0\)

\(1-\left(\frac{43}{8}+x+\frac{173}{24}\right):\frac{50}{3}=0\)

\(\left(\frac{151}{12}+x\right):\frac{50}{3}=1\)

\(\frac{151}{12}+x=\frac{50}{3}\)

\(x=\frac{50}{3}-\frac{151}{12}\).

\(x=\frac{49}{12}\)