a bank teller has 54 in $5 and $20 bill s. the total value is $780. how many 5 dollars are there
34
X+y=54
5x+20y=780
-5(x+y=54)
-5x-5y=-270
5x+20y=780
15y=510
Y=34
X=20
5(20)+20(34)=780
Five dollars bills = 20
X+y=54
5x+20y=510
To find the number of $5 bills, we can set up a system of equations based on the given information.
Let's say the number of $5 bills is "x". Since the teller has a total of 54 bills, we can determine the number of $20 bills by subtracting "x" from 54.
So, the number of $20 bills is 54 - x.
Now, let's calculate the total value of the $5 bills:
Value of $5 bills = number of $5 bills * $5 = x * $5 = 5x
Similarly, let's calculate the total value of the $20 bills:
Value of $20 bills = number of $20 bills * $20 = (54 - x) * $20 = 20(54 - x) = 1080 - 20x
We are given that the total value of the bills is $780. So we can set up the equation:
Total value = Value of $5 bills + Value of $20 bills
$780 = 5x + (1080 - 20x)
Simplifying the equation:
$780 = 5x + 1080 - 20x
Combining like terms:
$780 = -15x + 1080
Now, let's solve for x.
Subtracting 1080 from both sides:
$780 - $1080 = -15x + $1080 - $1080
-$300 = -15x
Dividing both sides by -15:
-$300/-15 = -15x/-15
20 = x
Therefore, there are 20 $5 bills.