A bill of $424 was paid with $5 bills and $2 bills. A total of 128 bills were used. How
many of them were fives?

Respuesta :

Answer: 56

Step-by-step explanation:

Let the number of $5 be x

Let the number of $2 be y.

Based on the information given, we can form an equation as:

x + y = 128 ........ i

5x + 2y = 424 ....... ii

Multiply equation i by 2

Multiply equation ii by 1

2x + 2y = 256 ...... iii

5x + 2y = 424 ....... iv

Subtract iii from iv

3x = 168

x = 168/3

x = 56.

Therefore, there were 56 $5 bills.