Question 892306
The factor, 1 does not do anything.
The factor, -1 on x simply makes this -x.


{{{y=abs(-x+5)+4}}}.


Either -x+5 is greater or equal to zero OR -x+5 is less than zero.


Either {{{abs(-x+5)=-x+5}}} and then
{{{y=-x+5+4}}}
{{{y=-x+9}}}


OR
{{{abs(-x+5)=x-5}}} and then
{{{y=x-5+4}}}
{{{y=x-1}}}


The critical value for x is at x=5, at which the sign of the absolute value input changes.  AT x=5, y=4.