Mimi wants to spend a $25 gift card on two kinds of in-app purchases for her favorite game: premium skins that cost $2.99, and tools that cost $4.99. Enter an equation that models the skins and tools that Mimi can afford with the gift card. Let S be the number of skins bought and let T be the number of tools bought, and do not include dollar signs in your answer.

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.