Formulate but do not solve the problem. Cantwell Associates, a
real estate developer, is planning to build a new apartment complex
consisting of x one-bedroom units, y two-bedroom townhouses, and z
three-bedroom townhouses. A total of 136 units are planned, and the
number of family units (two- and three-bedroom townhouses) will
equal the number of one-bedroom units. If the number of one-bedroom
units will be 2 times the number of three-bedroom units, find how
many units of each type will be in the complex.