a) \(\left|1,5x\right|-\left|0,6\right|=\left(-2\right)+\left|0,4\right|\)
\(\left|1,5x\right|-0,6=\left(-2\right)+0,4\)
\(\left|1,5x\right|-0,6=-1,6\)
\(\left|1,5x\right|=-1,6+0,6\)
\(\left|1,5x\right|=-1\)
\(\Rightarrow\) x không tồn tại
b) \(\left|3x+1\right|=2-\left|-\frac{4}{5}\right|\)
\(\left|3x+1\right|=2-\frac{4}{5}\)
\(\left|3x+1\right|=\frac{6}{5}\)
\(\Rightarrow3x+1\in\left\{\frac{6}{5};-\frac{6}{5}\right\}\)
\(\Rightarrow3x\in\left\{\frac{1}{5};\frac{-11}{5}\right\}\)
\(\Rightarrow x\in\left\{\frac{1}{15};\frac{-11}{15}\right\}\)
c)\(\left|1-2x\right|+4=\left|-10\frac{1}{2}\right|-\frac{1}{2}\)
\(\left|1-2x\right|+4=10\frac{1}{2}-\frac{1}{2}\)
\(\left|1-2x\right|+4=10\)
\(\left|1-2x\right|=10-4\)
\(\left|1-2x\right|=6\)
\(\Rightarrow1-2x\in\left\{6;-6\right\}\)
\(\Rightarrow2x\in\left\{-5;7\right\}\)
\(\Rightarrow2x\in\left\{-\frac{5}{2};\frac{7}{2}\right\}\)
d)\(\left|x+\frac{7}{3}\right|-\left|\frac{1}{3}\right|=0\)
\(\left|x+\frac{7}{3}\right|-\frac{1}{3}=0\)
\(\Rightarrow\left|x+\frac{7}{3}\right|=\frac{1}{3}\)
\(\Rightarrow x+\frac{7}{3}\in\left\{\frac{1}{3};\frac{-1}{3}\right\}\)
\(\Rightarrow x\in\left\{-2;\frac{-8}{3}\right\}\)
|1,5x|-|0,6|=(-2)+|0,4|
|1,5x|-0=(-2)+0,4
|1,5x|=-2+(0,4+0,6)
|1,5x|=-2+1=-1
mà GTTT của 1 số luôn luôn là số nguyên dương =>x\(\in\phi\)
b)|3x+1|=2-|4/5|
|3x+1|=2-4/5
|3x+1|=6/5
=>3x+1=6/5 hay 3x+1=-6/5
3x=6/5-1 hay 3x=-6/5-1
3x=1/5 hay 3x=-11/5
x=1/5:3 hay x=-11/5:3
x=1/15 hay x=-11/15
c)|1-2x|+4=|-10/1/2|-1/2
|1-2x|=-21/2-1/2-4
|1-2x|=-15
=>1-2x=15 hay 1-2x=-15
2x=1-15 hay 2x=1-(-15)
2x=-14 hay 2x=16
x=14/2 hay x=16/2
x=7 hay x=8
d)|x+7/3|-|1/3|=0
|x+7/3|-1/3=0
|x+7/3|=0+1/3
|x+7/3|=1/3
=>x+7/3=1/3 hay x+7/3=-1/3
x=1/3-7/3 hay x=-1/3-7/3
x=-6/3=-2 hay x=-8/3
