Question 366574
a clerk counts $1.00 and $10.00 bills at the end of the day he finds he has a total of 49 bills having a combined monetary value of $139 . find the number of bills of each denomination

Let x = the number of $1.00 bills
 49-x = the number of $10.00 bills

1.00x + 10.00(49-x) = 139
      x + 490 -10x  = 139

Combine like terms
              -9x   = 139-490
                x   = -351/-9
                x   = 39

             49-x   = 10

The clerk has 39 $1 bills and 10 $10 bills