Three grades of milk are 1 percent, 5 percent and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 5 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z gallons of a 7 percent grade, what is x in terms of y and z?
Choose the correct choice from the following options
A) -1y - 2z B) (y +z) / 4 C) 2y + 3z D) 3y + z E) 3y + 4.5z
Based on the given information, the following equation could be dervied: 1% * x + 5% * y + 3% * z = 7% * (x+y+z)   Then use algebra to figure out 6%*x = -2%*y - 4%*z. Thus, 3x = -1y - 2z.   -1y - 2z
<result>A</result>
Three grades of milk are 1 percent, 5 percent and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 5 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z gallons of a 7 percent grade, what is x in terms of y and z?