An emu-for-hire company has 20 emus they rent out to people with emu-related emergencies. There are 5 brown emus, 8 grey emus, 2 white emus, and the rest are multi-color. What is the probability that a customer will receive a multi-color emu?

Do you have a picture? ?

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.

Line ab is y = -7/5x + 56/5i don't understand  where point d comes into this.