Question

Help thanksssssssssssss

Answer 1

This question is read from left to right.
2x - y = 60% of 5y of means multiply.
2x - y = 60/100 * 5y = 300y /100 = 3y 
2x - y = 3y Add y to both sides.
2x = 4y Divide by 2
x = 2y
Now divide by x which is a bit unusual.
1 = 2y/x Now divide by 2
1/2 = y/x

C <<<< answer

Answer 2

First, translate the words you're given into math: 2x-y = 60% of 5y.
60% = 60/100 = 0.60. 
0.60(5y) = 3y

2x-y = 3y

>> If this is the SAT and you have to do percentage by hand, you can always use fractions. So, 60% = 60/100 = 6/10 = 3/5. $\frac{3}{5} * 5 = 3$. 
Another quick percentage trick is that 10% of anything is just that number with the decimal point moved to the left one space. For ex: 10% of 5 = 0.5. And then you can multiply 0.5 by 6 (because 10%*6 = 60%) to get 3.

Back to the problem:
Now you have 2x-y = 3y. You are looking for what $\frac{y}{x}$ equals to. Start by separating the x and y variables by putting them on opposite sides of the equal sign:
2x-y = 3y
2x = 4y

You want x and y on one side and numbers on the other side. You also want y to be on the top of the fraction. What you want to do is divide both sides by x first:
$2x = 4y\\ 2 = 4 \frac{y}{x}$

Finally, isolate the variables by dividing by 4 on both sides:
$2 = 4 \frac{y}{x} \\ \frac{y}{x} = \frac{2}{4} \\ \frac{y}{x} = \frac{1}{2}$

The answer is C) 1/2