Answer:
-18y=1
Step-by-step explanation:
Sorry if this is wrong, I was just guessing...
Can you list the answer choices?

would be equivalent
Answer:
18:27
Step-by-step explanation:
In the question the first one that is stated goes first then the other one. While finding a ratio it's pretty easy since all you have to do is 18:27 and done!
So you subtitute y=3x into
2x+y=15
so
2x+(3x)=15
add like terms
5x=15
divide both sides by 5
x=3
subtitute x=3 into first equation (y=3x)
y=3(3)
y=9