a, 14 - x - 10 = -9 + 15
=> - x = 6 - 14 + 10
=> - x = 2
=> x = -2
vay_
b, |x| + 5 + 7 = 10
=> |x| = -2
=> x thuoc tap hop rong
vay_
A) 14-x-10 = ( -9) + 15
14-x-10 = 6
14-x=6 + 10
14-x = 16
x = 14 - 16
x = -2
a,\(14-x-10=\left(-9\right)+15\)
\(-x=\left(-9\right)+15-14+10\)
\(x=-2\)
b,\(\left|x\right|=5+7-10\)
\(\left|x\right|=2\)
\(\Rightarrow x=\pm2\)
c,\(\left|x\right|=\left(-12\right)+\left(-15\right)+8\)
\(\Rightarrow\left|x\right|=-19\)
Vì \(\left|x\right|\ge0\Rightarrow x\in\varnothing\)
d,\(\left|x+5\right|=4-\left(-3\right)+5\)
\(\Rightarrow\left|x+5\right|=12\)
\(\Rightarrow\orbr{\begin{cases}x+5=12\\x+5=-12\end{cases}\Rightarrow\orbr{\begin{cases}x=7\\x=-17\end{cases}}}\)
\(\left|x\right|< 4\)
\(\Rightarrow x\in\left\{-4;-3;-2;-1;0;1;2;3\right\}\)