Question

A={x:x€R,-4<x<0} express in interval set​

Answer 1

A = {x: x€R, -4 < x < 0} express in interval set

=>

A = {x : x€R, -4 < x < 0}

This is Open Interval

A = x = (-4, 0)

(-4, 0) = {x: x € R, -4 < x < 0}

Let me tell you what is Open Interval ⬇️

Open Interval: Let a, b ∈ R and a < b then the set {x/x∈R, a < x < b} is called open interval and is denoted by (a,b). All the numbers between a and b belong to the open interval (a,b) but a, b themselves do not belonging to this interval.