3/5-2x/=7,5-(-4,5)                            \(\Rightarrow\)5-2x=4 hoặc 5-2x=-4                            Vậy x=0.5 hoặc 4.5

\(\Rightarrow\)3/5-2x/=7,5+4,5                      \(\Rightarrow\) 2x=5-4 hoặc2x=5-(-4)                      Nhớ tích nha!!!!!

\(\Rightarrow\)3/5-2x/=12                              \(\Rightarrow\)2x=1 hoặc 2x=9

\(\Rightarrow\)/5-2x/=12:3                              \(\Rightarrow\)x=1:2 hoặc x=9:2

\(\Rightarrow\)/5-2x/=4                                  \(\Rightarrow\)x=0.5 hoặc x=4.5

\(3\left|5-2x\right|=7,5+4,5\)

\(3\left|5-2x\right|=12\)

\(\left|5-2x\right|=12\div3=4\)

\(\Rightarrow5-2x=4\)hoặc \(5-2x=-4\)

\(5-2x=4\Rightarrow2x=5-4=1\Rightarrow x=\frac{1}{2}\)

\(5-2x=-4\Rightarrow2x=5+4=9\Rightarrow x=\frac{9}{2}=4,5\)

7,5 - 3 |5 - 2x| = -4,5 => -3 |5 - 2x| = -12 => |5 - 2x| = 4

=> 5 - 2x = 4 hoặc -4

=> -2x = -1 hoặc -9

=> x = 0,5 hoặc x = 4,5

\(7,5-3\left|5-2x\right|=-4,5\)

\(\Leftrightarrow3\left|5-2x\right|=7,5-\left[-4,5\right]\)

\(\Leftrightarrow3\left|5-2x\right|=7,5+4,5\)

\(\Leftrightarrow3\left|5-2x\right|=12\)

\(\Leftrightarrow\left|5-2x\right|=4\)

\(\Leftrightarrow\orbr{\begin{cases}5-2x=4\\5-2x=-4\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=\frac{9}{2}\end{cases}}\)

\(7,5-3\left|5-2x\right|=-4,5\)

\(\Leftrightarrow3\left|5-2x\right|=7,5-\left(-4,5\right)\)

\(\Leftrightarrow3\left|5-2x\right|=7,5+4,5\)

\(\Leftrightarrow3\left|5-2x\right|=12\)

\(\Leftrightarrow\left|5-2x\right|=12:3\)

\(\Leftrightarrow\orbr{\begin{cases}5-2x=4\\5-2x=-4\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}2x=5-4\\2x=5-\left(-4\right)\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}2x=1\\2x=9\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=1:2\\x=9:2\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=\frac{9}{2}\end{cases}}\)

~ Rất vui vì giúp đc bn ~

b) x = 1,75

câu a bạn chưa ghi x

cậu làm ơn ghi rõ lời giải ra đi

a: \(\left|-x+\frac25\right|+\frac12=3,5\)

=>\(\left|x-\frac25\right|=3,5-0,5=3\)

=>\(\left[\begin{array}{l}x-\frac25=3\\ x-\frac25=-3\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3+\frac25=\frac{17}{5}\\ x=-3+\frac25=-\frac{13}{5}\end{array}\right.\)

b: \(\frac{21}{5}+3:\left|\frac{x}{4}-\frac23\right|=6\)

=>\(3:\left|\frac14x-\frac23\right|=6-\frac{21}{5}=\frac95\)

=>\(\left|\frac14x-\frac23\right|=3:\frac95=3\cdot\frac59=\frac53\)

=>\(\left[\begin{array}{l}\frac14x-\frac23=\frac53\\ \frac14x-\frac23=-\frac53\end{array}\right.\Rightarrow\left[\begin{array}{l}\frac14x=\frac23+\frac53=\frac73\\ \frac14x=-\frac53+\frac23=-\frac33=-1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac73\cdot4=\frac{28}{3}\\ x=-1\cdot4=-4\end{array}\right.\)

c: 7,5-3|5-2x|=-4,5

=>3|5-2x|=7,5+4,5=12

=>3|2x-5|=12

=>|2x-5|=4

=>\(\left[\begin{array}{l}2x-5=4\\ 2x-5=-4\end{array}\right.\Rightarrow\left[\begin{array}{l}2x=9\\ 2x=1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac92\\ x=\frac12\end{array}\right.\)

d: \(\frac13-\left|\frac54-2x\right|=\frac14\)

=>\(\left|\frac54-2x\right|=\frac13-\frac14=\frac{1}{12}\)

=>\(\left|2x-\frac54\right|=\frac{1}{12}\)

=>\(\left[\begin{array}{l}2x-\frac54=\frac{1}{12}\\ 2x-\frac54=-\frac{1}{12}\end{array}\right.\Rightarrow\left[\begin{array}{l}2x=\frac54+\frac{1}{12}=\frac{16}{12}=\frac43\\ 2x=\frac54-\frac{1}{12}=\frac{15}{12}-\frac{1}{12}=\frac{14}{12}=\frac76\end{array}\right.\)

=>\(\left[\begin{array}{l}x=\frac23\\ x=\frac{7}{12}\end{array}\right.\)

e: \(\frac{21}{5}+3:\left|\frac{x}{4}-\frac23\right|=6\)

=>\(3:\left|\frac14x-\frac23\right|=6-\frac{21}{5}=\frac95\)

=>\(\left|\frac14x-\frac23\right|=3:\frac95=3\cdot\frac59=\frac53\)

=>\(\left[\begin{array}{l}\frac14x-\frac23=\frac53\\ \frac14x-\frac23=-\frac53\end{array}\right.\Rightarrow\left[\begin{array}{l}\frac14x=\frac23+\frac53=\frac73\\ \frac14x=-\frac53+\frac23=-\frac33=-1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac73\cdot4=\frac{28}{3}\\ x=-1\cdot4=-4\end{array}\right.\)

a: Ta có: \(\left|\dfrac{2}{5}-x\right|+\dfrac{1}{2}=3.5\)

\(\Leftrightarrow\left|x-\dfrac{2}{5}\right|=3\)

\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{2}{5}=3\\x-\dfrac{2}{5}=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{17}{5}\\x=-\dfrac{13}{5}\end{matrix}\right.\)

b: Ta có: \(\dfrac{21}{5}+3:\left|\dfrac{x}{4}-\dfrac{2}{3}\right|=6\)

\(\Leftrightarrow3:\left|\dfrac{1}{4}x-\dfrac{2}{3}\right|=6-\dfrac{21}{5}=\dfrac{9}{5}\)

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

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{4}x-\dfrac{2}{3}=\dfrac{5}{3}\\\dfrac{1}{4}x-\dfrac{2}{3}=-\dfrac{5}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{4}x=\dfrac{7}{3}\\\dfrac{1}{4}x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{28}{3}\\x=-4\end{matrix}\right.\)

em muốn hỏi là tại sao 3,5 bên trên xuống dưới lại là 3 và -x +2/5 của em xuống dưới lại chuyển thành x-2/5 ạ mong anh giải đáp