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 \(5-2x=-4\)

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

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

=> 3.|5-2x|=7,5-(-4,5)

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

=>|5-2x|=12:3=4

=>5x-2=4 (luôn luôn lớn hơn hoặc bằng 0)

=>5x=4+2=6

=>x=6:5 

Vậy x=1,2

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

b) x = 1,75

câu a bạn chưa ghi x

cậu làm ơn ghi rõ lời giải ra đi

để tớ viết lại câu a

7,5 . 1 3/4=6 2/5

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

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

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

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

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