Algebra 2 Homework

Question

A student has some $1 bills and $5 bills in his wallet. He has a total of 16 bills that are worth $40. How much of each type of bill does he have?

Answer 1

To solve this problem, use a system of equations:

Let x be the amount of 1$ bills and let y be the amount of 5$ bills.

He has a total of 16 bills that are worth $40. 

X + Y = 16

1X + 5 Y = 40

We will first solve for X in the first equation and substitute it into the second equation:

X = 16 - Y

1(16 - Y) + 5 Y = 40

16 - Y + 5 Y = 40

16 + 4 Y = 40

4Y = 24

Y = 6

Substitute back into first equation:

X + Y = 16

X + 6 = 16

X = 10

There will be 10 1$ bills and 6 $5 bills.

To check the answers, plug each back into the original equation.