Question

tim so nguyen x biet

a,|x|+5=21

b,-2<hoac=x-1<2

Answer 1

a)

 /x/  + 5 =21

(=) /x/=21-5=16

=> x = 16 hoặc x= -16

b) \(-2\le x-1\)<  2

=> x-1 \(\in\){ -2 ; -1 ; 0 ; 1 }

=> x \(\in\){-1 ; 0 ; 1 ; 2 }

Answer 2

a,\(\left|x\right|+5=21\)

   \(\left|x\right|=21-5=16\)

=>\(x=16\) hoặc \(x=-16\)

b, \(-2\le x-1< 2\)

\(=>x-1\in\left\{-2;-1;0;1\right\}\)

\(=>1\in\left\{-1;0;1;2\right\}\)

Answer 3

a,\(|x|=21-5\)

\(|x|=16\)

\(\Rightarrow\hept{\begin{cases}x=16\\x=-16\end{cases}}\)