Answer :
You have to think about what y and x can be equal to for you to get 12. (Hint: y is going to be a bigger number than x)
Ex: 3y-5x=5
Think: 3 x 10(y) - 5 x 5(x)= 5
So, y would be 10 and x would be 5.
Ex: 3y-5x=5
Think: 3 x 10(y) - 5 x 5(x)= 5
So, y would be 10 and x would be 5.