Question

| 2x-4 |(меньше или равно) 8

Answer 1

$|2x-4| leq 8; \ |f(x)| leq c; \ left { {{f(x) leq c} atop {f(x) geq -c;}} right. textless = textgreater -c leq f(x) leq c; \ -8 leq 2x-4 leq 8; \ -8+4 leq 2x leq 8+4; \ -4:2 leq x leq 12:2; \ -2 leq x leq 6; \ xin[-2;6].$