Me on my question
plz explain

1)Equation for the first piece , we can find using point-point equation for linear function
(y-y1)/(x-x1)=(y-y2)/(x-x2)
First point (-3,0)
Second point (-1,2)
(y-0)/(x+3)=(y-2)/(x+1)
y(x+1)=(y-2)(x+3)
yx+y=yx-2x+3y-6
3y-y=2x+6
2y=2x+6
y=x+3
f(x)=x+3 is first piece
2) It is a horizontal line, so f(x)=5 is second piece 

The clear answer is clearly 25 is very clear to me