Answer:
x = 72
Explanation:
We set the two equal to each other
x = 12/y = 9 is equal to x/y = 54.
In order for 9 to get to 54, you have to multiply it by 6. Since you multiplied the denominator with 6, you have to do the same with the numerator. 12 times 6 is 72.
x = 72