Question

Cum se face la 2??????

Answer 1

 

$\displaystyle\bf\\A=\Big\{x\in Z\Big|~|x|\leq4\Big\}\\\\\textbf{Rezolvam inecuatia.}\\\\|x|\leq4\\\\-4\leq x\leq4\\\\x\in\{-4;~-3;~-2;~-1;~0;~1;~2;~3;~4\}\\\\A=\{-4;~-3;~-2;~-1;~0;~1;~2;~3;~4\}\\\\S=(-4)+(-3)+(-2)+(-1)+0+1+2+3+4\\\\S=-4-3-2-1+0+1+2+3+4=-10+0+10=\boxed{\bf0}$