You wad up a piece of paper and throw it into the wastebasket. How far will your piece of paper travel if you throw it with a velocity of 3.1 m/s at an angle
of 32°? (Assume no air resistance and that the paper lands at the same
height you threw it from.)

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.