Question

Como resolver a equação modular l x - 5 l = 9???

Answer 1

$|x-5|=9\\\\\\(I)~x-5=9~~~~ou~~~~(II)~x-5=-9\\\\\\\\(I)~~x-5=9\to x=9+5\to \boxed{14}\\\\\\(II)~~ x-5=-9\to x=-9+5\to \boxed{x=-4}\\\\\\\\ \boxed{S=\{-4~;; 14\}}$