2 points...(1.25,85) & (1.75, 65)
draw strate line tween em
deltax=0.5, deltay=-20, slope=deltay/deltax=-20/0.5=-40
get out yer graf paper & get tu werk
or make quashun...y=-40x+konst
yu kood projekt this bak tu x=0... from 1 point such as (1.25,85)
deltax=-1.25, deltay=slope*deltax=-40*(-1.25)=+50
y at x=0....85+50=135