algebra
posted by kc .
a bank teller has 52 $5 and $10 bills in her cash drawer. the value of the bills is $460. how many $5 bills are there?

add up the value of the bills:
5x + 10(52x) = 460
5x + 520  10x = 460
5x = 60
x = 12
check:
5(12) + 10(40) = 60 + 400 = 460