12.     paul bought 9 total shirts for a total of $72. tee shirts cost $10 and long sleeve shirts cost $7. how many of each type of shirt did he buy?                 a.  3 tee shirts and 6 long sleeve shirts      b.  5 tee shirts and 4 long sleeve shirts      c.  7 tee shirts and 2 long sleeve shirts      d.  4 tee shirts and 5 long sleeve shirts

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle. he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field