1 2 points Carlos has taken an initial dose of his medication. After an hour he has 8mg in his bloodstream, then after 2 hours he has 3.2mg in his bloodstream. then after 3 hours he has 1.28mg remaining in his bloodstream. Write an equation that represents the amount of medication in Carlos' bloodstream over time.​

I’m pretty sure the answer is a

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.