a.1/4

b.-7/144

c.25/21

d.17/7

e.80/63

f.9/7

a)1/4

b)-7/144

c)-25/21

d)17/7

e)16/63

f)9/7

Tự làm đi, lười thế

a) x= 1/4

b) x= -7/144

c) x= 25/6

d) x=17/7

e) x= 80/63

f) x= -45/14

\(\dfrac{x-\dfrac{x}{12}+\dfrac{x}{18}}{7-\dfrac{7}{12}+\dfrac{7}{18}}=-\dfrac{4}{7}\\ \dfrac{x\left(1-\dfrac{1}{12}+\dfrac{1}{18}\right)}{7\left(1-\dfrac{1}{12}+\dfrac{1}{18}\right)}=-\dfrac{4}{7}\\ \dfrac{x}{7}=-\dfrac{4}{7}\\ x=-4\)

-12+3(-x+7)=-18

-12-3x+21=-18

9-3x=-18

3x=27

x=9

- 12 + 3 ( - x + 7 ) = - 18

- 3x + 3 . 7 = -18 + 12

- 3x + 21 = - 6

- 3 x = - 6 - 21

- 3x = - 27

x = - 27 : ( - 3 )

x = 9

-12 + 3( -x + 7 ) = -18

-12 - 3x + 21 = -18

9 - 3x = -18

3x = 27

x = 9

Mong mọi người giúp mình với ạ

\(a,y\times7+y\times3=70\\ \Rightarrow y\times\left(7+3\right)=70\\ \Rightarrow y\times10=70\\ \Rightarrow y=7\\ b,18:y+12:y=3\\ \Rightarrow\left(18+12\right):y=3\\ \Rightarrow30:y=3\\ \Rightarrow y=10\)

y x 7 + y x 3 = 70

y x ( 7 + 3 )  = 70

y x 10          = 70 : 10

y                  = 7

18 : y + 12 : y = 3

( 18 + 12 ) : y = 3

30 : y             = 3

y                    = 30 : 3

y                    = 10

a: \(x\in\left\{18;-18\right\}\)

\(a,\Rightarrow\left[{}\begin{matrix}x=18\\x=-18\end{matrix}\right.\\ b,\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{5}\\x=-\dfrac{3}{5}\end{matrix}\right.\\ c,\Rightarrow x:\left(-\dfrac{1}{60}\right)=2\Rightarrow-60.x=2\Rightarrow x=-\dfrac{2}{60}=-\dfrac{1}{30}\)

a.

\(10-2\left(4-3x\right)=-4\)

\(\Leftrightarrow2\left(4-3x\right)=10+4\)

\(\Leftrightarrow2\left(4-3x\right)=14\)

\(\Leftrightarrow4-3x=7\)

\(\Leftrightarrow3x=-3\)

\(\Leftrightarrow x=-1\)

b.

\(-12+3\left(-x+7\right)=-18\)

\(\Leftrightarrow3\left(-x+7\right)=-18+12=-6\)

\(\Leftrightarrow-x+7=-6:3=-2\)

\(\Leftrightarrow x=9\)

c.

\(-45:5.\left(-3-2x\right)=3\)

\(\Leftrightarrow-9.\left(-3-2x\right)=3\)

\(\Leftrightarrow-3-2x=-\dfrac{1}{3}\)

\(\Leftrightarrow2x=-\dfrac{8}{3}\)

\(\Leftrightarrow x=-\dfrac{4}{3}\notin Z\left(loại\right)\)

Câu này em ghi sai đề?

d.

\(3x-28=x+36\)

\(\Leftrightarrow2x=28+36\)

\(\Leftrightarrow2x=64\)

\(\Leftrightarrow x=32\)

e.

\(\left(-12\right)^2.x=56+10.13x\)

\(\Leftrightarrow144x=56+130x\)

\(\Leftrightarrow144x-130x=56\)

\(\Leftrightarrow14x=56\)

\(\Leftrightarrow x=4\)

c: Ta có: \(\left|x+\dfrac{5}{6}\right|:\dfrac{4}{5}=\dfrac{3}{8}\)

\(\Leftrightarrow\left|x+\dfrac{5}{6}\right|=\dfrac{3}{8}\cdot\dfrac{4}{5}=\dfrac{3}{10}\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{5}{6}=\dfrac{3}{10}\\x+\dfrac{5}{6}=-\dfrac{3}{10}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-8}{15}\\x=-\dfrac{17}{15}\end{matrix}\right.\)