y=a*abs(x-15)+23
abs equashuns hav 2 strate line segments:
1 go up, other go down
chaenj weer abs=0
this equashun, abs=0 at x=15
point=(15,23)
rite av that, line go up with slope=a
left side, line go down
zampel: at x=0, abs(x-15)=15, & y av point=15a+23