Question 182066
Let the number of $1 bills = x, so then number of $10 bills is 51-x.
From the problem description, you can write:
x($1)+(51-x)($10) = $213 Simplify and solve for x.
x+510-10x = 213
-9x+510 = 213 Add 510 to both sides.
-9x = -297 Divide both sides by -9
x = 33 and 51-x = 51-33 = 18.
The motel clerk has 33 $1 bills and 18 $10 bills.