Answer:
Y=5/2x-3
Step-by-step explanation:
The equation's slope is -4/10, which simplifies to -2/5. The reciprical of this, 5/2, is the slope of a perpendicular line. The first possibility you commented is the only one to have this slope.
2:3:5 = 480:720:1200
(a) 480+720+1200
(b) 480
(c) 720/(a)
11 quarters and 18 dimes
Hope this helps! :D