(6/10)x = (18/?)y
The right way would be to cross multiply.
10 * 18 = 180.
6 * 1 = 6
Divide.
180/6 = 30
The answer is 30.
So when x = 10, y = 30.
Way I would do it is to just divide 18 by 6, which gives you 3.
Multiply 3 with 10 to equal 30, and there is your answer for y.