Can someone help me understand how you end up with A in this question, I am not able to get anything remotely close to A. Detailed explanation would be much appreciated:

I realize the some of this is cut off, this is the question: Three grades of Milk are 1%, 2%, and 3% fat by volume. If x gallons of the 1% grade, y gallons of the 2% grade, and z gallons of 3% grade are mixed to give x+y+z gallons of 1.5% grade, what is x in terms of y and z?

I realize the some of this is cut off, this is the question: Three grades of Milk are 1%, 2%, and 3% fat by volume. If x gallons of the 1% grade, y gallons of the 2% grade, and z gallons of 3% grade are mixed to give x+y+z gallons of 1.5% grade, what is x in terms of y and z?












