Answer:
209 : 40 or 5.225 : 1
Step-by-step explanation:
Your calculator can tell you the ratio 8.36/1.60 is 5.225. Writing that decimal as a fraction, you can factor out 25 to get ...
8.36 : 1.6 = 5.225 : 1 = 5225 : 1000 = (25)(209) : (25)(40) = 209 : 40
So firstly, subtract x on both sides: 
Next, divide -2 on both sides, and your answer will be y = 1/2x - 3/2 , or the last option.