e gõ latex hoặc vt r chụp lên nhé như vầy ko nhìn đc cái đề nx e

a) \(2\dfrac{3}{4}-\left(\dfrac{1}{7}+1\dfrac{3}{4}\right)\)

\(=\dfrac{11}{4}-\dfrac{1}{7}-\dfrac{7}{4}=\left(\dfrac{11}{4}-\dfrac{7}{4}\right)-\dfrac{1}{7}=1-\dfrac{1}{7}=\dfrac{6}{7}\)

b) \(\dfrac{7}{-25}+\dfrac{-18}{25}+\dfrac{4}{23}+\dfrac{5}{7}+\dfrac{19}{23}\)

\(=\left(\dfrac{-7}{25}+\dfrac{-18}{25}\right)+\left(\dfrac{4}{23}+\dfrac{19}{23}\right)+\dfrac{5}{7}=-1+1+\dfrac{5}{7}=\dfrac{5}{7}\)

c) \(\dfrac{-1}{4}\left(12\dfrac{3}{4}-7,75\right)-25\%.3\dfrac{1}{2}\)

\(=\dfrac{-1}{4}\left(12\dfrac{3}{4}-7\dfrac{3}{4}\right)-\dfrac{1}{4}.\dfrac{7}{2}=\dfrac{-1}{4}.5-\dfrac{7}{8}\\ =-\dfrac{5}{4}-\dfrac{7}{8}=-\dfrac{17}{8}\)

(\(\frac45:\frac65\) + \(\frac15\) : \(\frac{1}{x}\)) x 30 - 26 = 54

(\(\frac45\times\frac56\) + \(\frac15\times x\)) x 30 = 54 + 26

(\(\frac23+\frac15x\)) x 30 = 80

\(\frac23+\frac15x\) = 80 : 30

\(\frac23+\frac15x=\frac83\)

\(\frac15x=\frac83-\frac23\)

\(\frac15x\) = 2

\(x=2:\frac15\)

\(x=2\times5\)

\(x=10\)

Vậy \(x=10\)

6,3 x y + 3,7 x y = 100

y x (6,3 + 3,7) = 100

y x 10 = 100

y = 100 : 10

y = 10

Vậy y = 10

mk sắp phải đi học rồi các bạn giúp mình với có đc ko mk nhớ sẽ đền đáp công ơn của bạn 

a) (5 - x) +12 = -25

<-> 5 - x + 12 = -25

<-> 17 - x = - 25

<-> x = 42

b) 12 - 4(x - 2) = -4

<-> 12 - 4x + 8 = -4

<-> 20 - 4x = -4

<-> 4x = 24

<-> x = 6

a) x- 25%x= 1/2<=>x-1/4x=1/2<=>3/4x=1/2<=>x=1/2:3/4=2/3

b)\(\left(50\%x+2\frac{1}{4}\right).\frac{-2}{3}=\frac{17}{6}\Leftrightarrow-\frac{1}{3}x-\frac{3}{2}=\frac{17}{6}\Leftrightarrow x=-13\)

c)\(\left(3\frac{x}{7}+1\right):\left(-4\right)=\frac{-1}{28}\Leftrightarrow\frac{28+x}{7}:\left(-4\right)=\frac{-1}{28}\Leftrightarrow\frac{28+x}{-28}=\frac{1}{-28}\Leftrightarrow28+x=1\Leftrightarrow x=-27\)

d)\(\left(1\frac{1}{3}-25\%-\frac{5}{12}\right)-2x=1,6:\frac{3}{5}\Leftrightarrow\frac{2}{3}-2x=\frac{8}{3}\Leftrightarrow x=-1\)

a)x-25%x=1/2

x-1/4x=1/2

x.(1-1/4)=1/2

x.3/4=1/2

x=1/2:3/4

x=2/3

a)\(\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)

\(=\frac{-7}{25}.\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=\frac{-7}{25}.1-\frac{18}{25}\)

\(=-\frac{7}{25}-\frac{18}{25}\)

\(=-1\)

b)\(\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{12}\)

\(=\frac{5}{7}.\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)

\(=\frac{5}{7}.\left(\frac{4}{12}-\frac{3}{12}-\frac{1}{12}\right)\)

\(=\frac{5}{7}.0\)

\(=0\)

a) \(\dfrac{-3}{8}-\dfrac{1}{8}:x=-5\dfrac{1}{4}-2\dfrac{1}{4}\)

\(\dfrac{-3}{8}-\dfrac{1}{8}:x=\dfrac{-21}{4}-\dfrac{9}{4}\)

\(\dfrac{-3}{8}-\dfrac{1}{8}:x=\dfrac{-15}{2}\)

\(\dfrac{1}{8}:x=\dfrac{-3}{8}-\dfrac{-15}{2}\)

\(\dfrac{1}{8}:x=\dfrac{57}{8}\)

\(x=\dfrac{1}{8}:\dfrac{57}{8}\)

\(x=\dfrac{1}{57}\)

b) \(\left(1\dfrac{1}{3}-25\%-\dfrac{5}{12}\right)-2x=1,6:\dfrac{3}{5}\)

\(\left(1\dfrac{1}{3}-\dfrac{1}{4}-\dfrac{5}{12}\right)-2x=\dfrac{8}{5}:\dfrac{3}{5}\)

\(\left(\dfrac{4}{3}-\dfrac{1}{4}-\dfrac{5}{12}\right)-2x=\dfrac{8}{3}\)

\(\left(\dfrac{13}{12}-\dfrac{5}{12}\right)-2x=\dfrac{8}{3}\)

\(\dfrac{2}{3}-2x=\dfrac{8}{3}\)

\(2x=\dfrac{2}{3}-\dfrac{8}{3}\)

\(2x=-2\)

\(x=\left(-2\right):2\)

\(x=-1\)

\(a;\dfrac{2}{3}x-50\%x-\left(-\dfrac{4}{5}\right):1\dfrac{3}{5}=-0,12+1\dfrac{3}{25}\\ \dfrac{1}{6}x+\dfrac{1}{2}=1\Rightarrow\dfrac{1}{6}x=1-\dfrac{1}{2}=\dfrac{1}{2}\\ \Rightarrow x=\dfrac{1}{2}:\dfrac{1}{6}=3\\ b;\left(-1\dfrac{1}{6}+\dfrac{2}{3}-\dfrac{3}{4}\right):x+\left(-1\dfrac{11}{12}\right)\cdot1\dfrac{21}{23}=-6\dfrac{1}{3}\\ -\dfrac{5}{4}:x-\dfrac{11}{3}=-\dfrac{19}{3}\\ -\dfrac{5}{4}:x=-\dfrac{19}{3}+\dfrac{11}{3}=-\dfrac{8}{3}\\ x=-\dfrac{5}{4}:\left(-\dfrac{8}{3}\right)=\dfrac{15}{32}\\ c;50\%x-\dfrac{1}{3}x-\left(-\dfrac{2}{3}\right)^2\cdot\left(-1\dfrac{1}{8}\right)=-119\dfrac{3}{4}+120\dfrac{5}{6}\\ \dfrac{1}{6}x+\dfrac{1}{2}=\dfrac{13}{12}\Rightarrow\dfrac{1}{6}x=\dfrac{13}{12}-\dfrac{1}{2}=\dfrac{7}{12}\\ x=\dfrac{7}{12}:\dfrac{1}{6}=\dfrac{7}{2}\)

Bài 6:

a: \(x=-\dfrac{2}{3}-\dfrac{1}{7}=\dfrac{-14-3}{21}=\dfrac{-17}{21}\)

d: \(x=\dfrac{9}{10}\cdot\dfrac{-5}{9}=\dfrac{-1}{2}\)

e: \(\Leftrightarrow x\cdot\dfrac{1}{3}=\dfrac{14}{21}-\dfrac{3}{21}=\dfrac{11}{21}\)

=>x=11/7

câu 1 : là -4

câu 2 : là -1

nếu đúng hãy cho mình 1 k đúng nhé

GIẢI HẲN RA HỘ MK VỚI !!

a) \(x^3-\frac{4}{25}x=0\)

\(\Leftrightarrow x\left(x+\frac{2}{5}\right)\left(x-\frac{2}{5}\right)=0\)

<=> x = 0

Xét 2 trường hợp: 

\(\Leftrightarrow x+\frac{2}{5}=0\)

      \(x=0-\frac{2}{5}\)

      \(x=-\frac{2}{5}\)

\(\Leftrightarrow x-\frac{2}{5}=0\)

      \(x=0+\frac{2}{5}\)

      \(x=\frac{2}{5}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x=\pm\frac{2}{5}\end{cases}}\)

b) \(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

\(=\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{4}{3}\)

\(=\frac{13}{40}:\frac{4}{3}\)

\(=\frac{39}{120}=\frac{13}{40}\)

c) \(4\left(\frac{-1}{2}\right)^3-2\left(\frac{-1}{2}\right)^2+3\left(\frac{-1}{2}\right)-1\left(\frac{-1}{2}\right)^0\)

\(=4\left(\frac{-1}{2}\right)^3-2\left(\frac{-1}{2}\right)^3+3\left(\frac{-1}{2}\right)-1.1\)

\(=-\frac{1}{2}-\frac{1}{2}-\frac{3}{2}-1.1\)

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

\(=-\frac{7}{2}\)