Please help me on this question. 15. A cube of metal weighs 1,800 g and displaces 600 mL of water when immersed into it. Find the density of the metal.

A.3 g/mL
B. 2,400 g/mL
C. 1,080,000 g/ml
D. 0.33 g/mL

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.

The answer would be 2 times 3 plus 8 divided by 8 = 7