What is the slope of a line that goes through (0,6) and (6,0)

(x1,y1)=(0,6)
(x2,y2)=(6,0)
slope=(0-6)/(6-0)=0

The answer is c because you turn 17.5% into a decimal which gives you .175 then you times that by $361.35 which gives you 63.23625 but then you round that which gives you 63.24. then you at 63.24 pulse 361.35 and you round it which gives you $425