A cash register contains 5 bills and 10 bills with a total v

A cash register contains $5 bills and $10 bills with a total value of $320. If there are 43 bills total, then how many of each does the register contain?

Let the number of $5 bill is x and the number of $10 bill is y
then
x+ y = 43 ---------eqn 1
5x +10y = 320 -------------eqn 2
Multiply eqn 1 with 5
5x + 5y = 215 --------eqn 3
subtracting eqn 3 from 2
5y = 320 - 215
y = 21
so, x= 22
Answer:
number of $5 bill = 22
number of $10ill = 21