9,678

a, 0,09 x m - 5,8 = 34,52 

=> 0,09 x m = 34,52 + 5,8

=> 0,09 x m = 40,32

=> m = 40,32 : 0,09 

=> m = 448

b,m x 2,5 + m x 7,5 = 967,8

=> m x ( 2,5 + 7,5 ) = 967,8 

=> m x 10 = 967,8

=> m = 967,8 : 10 

=> m = 96,78 

a,0.9*m=34.52+5.8

0.9*m=  40.32

40.32:0.9

m=44.8

b,(2.5+7.5)*m=967.8

m=967.8:10

=96.78

\(M.2,5+M.7,5=967,8\)

\(M.10=967,8\)

\(M=96,78\)

Vậy ...

\(y:2,5+9,6\cdot y=7,5-3\)

\(y:\frac{25}{10}+9,6\cdot y=4,5\)

\(y\cdot\frac{10}{25}+9,6\cdot y=4,5\)

\(y\cdot0,4+9,6\cdot y=4,5\)

\(y\left(0,4+9,6\right)=4,5\)

\(y\cdot10=4,5\)

\(\Rightarrow y=0,45\)

P/s: Hoq chắc :<

y : 2,5 + 9,6 x y = 7,5 - 3

y : \(\frac{25}{10}\) + \(\frac{96}{10}\) x y = 3,5

y x \(\frac{10}{25}\)+ \(\frac{96}{10}\) x y = 3,5

y x (\(\frac{2}{5}+\frac{48}{5}\)) = \(\frac{35}{10}\)

y x \(\frac{50}{5}\)= \(\frac{7}{2}\)

y x 10 = \(\frac{7}{2}\)

y         = \(\frac{7}{2}\) : 10

y         = \(\frac{7}{2}\) x \(\frac{1}{10}\)

y         = \(\frac{7}{20}\)

Ko bik đúng hay ko nữa, sai thì thui đừng k sai nha

a) \(y:10+y.3,9=4,8\)

\(\Rightarrow y.0,1+y.3,9=4,8\)

\(\Rightarrow y.\left(0,1+3,9\right)=4,8\)

\(\Rightarrow y.4=4,8\)

\(\Rightarrow y=1,2\)

Vậy y = 1,2

b) \(y.2,5+y.7,5=12,8\)

\(\Rightarrow y.\left(2,5+7,5\right)=12,8\)

\(\Rightarrow y.10=12,8\)

\(\Rightarrow y=1,28\)

Vậy y = 1,28

chấm là j vậy

a: =>4y=4,8

=>y=1,2

b: =>10y=12,8

=>y=1,28

a)\(\left|2x\right|-\left|-2,5\right|=\left|-7,5\right|\)

\(\Rightarrow\left|2x\right|-2,5=7,5\)

\(\Rightarrow\left|2x\right|=10\)

\(\Rightarrow\left[{}\begin{matrix}2x=10\Rightarrow x=5\\2x=-10\Rightarrow x=-5\end{matrix}\right.\)

b) \(\left|2x-3\right|=1\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=1\Rightarrow2x=4\Rightarrow x=2\\2x-3=-1\Rightarrow2x=2\Rightarrow x=1\end{matrix}\right.\)

c) \(\left|x-3,5\right|+\left|y-1,3\right|=0\)

Ta có: \(\left|x-3,5\right|\ge0\forall x\)

\(\left|y-1,3\right|\ge0\forall y\)

\(\Rightarrow\left|x-3,5\right|+\left|y-1,3\right|\ge0\forall x,y\)

Dấu "=" xảy ra

\(\Leftrightarrow\left\{{}\begin{matrix}x-3,5=0\Rightarrow x=3,5\\y-1,3=0\Rightarrow y=1,3\end{matrix}\right.\)

\(a)\left|2x\right|-\left|-2,5\right|=\left|-7,5\right|\)

\(\Rightarrow\left|2x\right|-2,5=7,5\)

\(\Rightarrow\left|2x\right|=10\)

\(\Rightarrow\left[{}\begin{matrix}2x=10\Rightarrow x=5\\2x=-10\Rightarrow x=-5\end{matrix}\right.\)

Vậy ...............

\(b)\left|2x-3\right|=1\)

\(\Rightarrow\left|2x\right|-3=1\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=1\Rightarrow2x=4\Rightarrow x=2\\2x-3=-1\Rightarrow2x=2\Rightarrow x=1\end{matrix}\right.\)

Vậy .........

\(c)\left|x-3,5\right|+\left|y-1,3\right|=0\)

\(\Rightarrow\left[{}\begin{matrix}x-3,5=0\Rightarrow x=3,5\\y-1,3=0\Rightarrow y=1,3\end{matrix}\right.\)

Vậy ..............

Chúc bạn học tốt!