a,|x|+3=5
\(\Leftrightarrow\left|x\right|=5-3=2\)
\(\Rightarrow x=\left\{{}\begin{matrix}2\\-2\end{matrix}\right.\)
b,|x+3|=5
\(\Rightarrow\left\{{}\begin{matrix}x+3=5\\x+3=-5\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}2\\-8\end{matrix}\right.\)
c,|x-7|+13=25
<=>|x-7|=25-13=12
\(\Rightarrow\left\{{}\begin{matrix}x-7=12\\x-7=-12\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=19\\x=-5\end{matrix}\right.\)
d,\(26-\left|x+9\right|=-13\)
\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)=39\)
\(\Rightarrow\left\{{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=30\\x=-48\end{matrix}\right.\)
e,8-|x|=15
<=>|x|=8-15=-7
\(\Rightarrow\left\{{}\begin{matrix}x=-7\\x=7\end{matrix}\right.\)
f,6-|-3+x|=-15
\(\Leftrightarrow\left|-3+x\right|=6-\left(-15\right)=21\)
\(\Rightarrow\left\{{}\begin{matrix}-3+x=21\\-3+x=-21\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=24\\x=-18\end{matrix}\right.\)
a, |x| + 3 = 5
|x| = 5 - 3
|x| = 2
|x| = 2 hoặc |x| = -2
Vậy |x| thuộc {2; -2}
b,|x + 3| = 5
|x + 3| = 5 hoặc |x + 3| = -5
x = 5 - 3 x = (-5) - 3
x = 2 x = -8
Vậy x thuộc {2; -8}
c,|x - 7| + 13 = 25
|x - 7| = 25 - 13
|x - 7| = 12
|x - 7| = 12 hoặc |x - 7| = -12
x = 12 + 7 x = (-12) + 7
x = 19 x = -5
Vậy x thuộc {19 ; -5}
a,|x|+3=5
⇔|x|=5−3=2⇔|x|=5−3=2
⇒x={2−2⇒x={2−2
b,|x+3|=5
⇒{x+3=5x+3=−5⇒{2−8⇒{x+3=5x+3=−5⇒{2−8
c,|x-7|+13=25
<=>|x-7|=25-13=12
⇒{x−7=12x−7=−12⇒{x=19x=−5⇒{x−7=12x−7=−12⇒{x=19x=−5
d,26−|x+9|=−1326−|x+9|=−13
⇔|x+9|=26−(−13)=39⇔|x+9|=26−(−13)=39
⇒{x+9=39x+9=−39⇒{x=30x=−48⇒{x+9=39x+9=−39⇒{x=30x=−48
e,8-|x|=15
<=>|x|=8-15=-7
⇒{x=−7x=7⇒{x=−7x=7
f,6-|-3+x|=-15
⇔|−3+x|=6−(−15)=21⇔|−3+x|=6−(−15)=21
⇒{−3+x=21−3+x=−21⇒{x=24x=−18⇒{−3+x=21−3+x=−21⇒{x=24x=−18
