Chapter 7 of the Jiuzhang suanshu presents a problem of two linear equations involving acres of land and their respective prices. One of the two equations can be translated to: 300x + y = 10000 If y = 87.5, what is the value for x? 300x + y = 10,000 300x + (87.5) = 10,000 300x + 6,250 = 10,000 x =