Answer: x ≥ -5
Explanation:
First, let's see how the function f(x) = IxI works:
if x ≥ 0, IxI = x
if x ≤ 0, IxI = -x
Notice that for 0, I0I = 0.
Ok, we want that:
|x+5| = x+5
Notice that this is equivalent to:
IxI = x
This means that |x+5| = x+5 is only true when:
(x + 5) ≥ 0
from this we can find the possible values of x:
we can subtract 5 to both sides and get:
(x + 5) -5 ≥ 0 - 5
x ≥ -5
So the graph in the number line will be a black dot in x = -5, and all the right region shaded.
something like:
-7__-6__-5__-4__-3__-2__-1__0__1__2__3__4__ ...