Question

решите двойное неравенство -1<1+2х /4 <3

Answer 1

$-1<\frac{1+2x}{4} <3 \ , \ |*4\\\\-4<1+2x<12\\\\-4-1<1+2x-1<12-1\\\\-5<2x<11\\\\-2,5<x<5,5\\\\\boxed{x\in(-2,5 \ ; \ 5,5)}$