a, - 4< x < 3

\(x\in\left\{-3;-2;-1;0;1;2\right\}\)

\(x=\left(-3\right)+\left[\left(-2\right)+2\right]+\left[\left(-1+1\right)\right]+0\)

\(x=\left(-3\right)+0+0+0\)

\(x=\left(-3\right)\)

b, \(-5< x< 5\)

\(x\in\left\{-4;-3;-2;-1;0;1;2;3;4\right\}\)

\(x=\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+\left[\left(-2\right)+2\right]+\left[\left(-1\right)+1\right]+0\)

\(x=0+0+0+0+0\)