A tip jar contains x one-dollar bills and y five- dollar bills. There are 42 bills in the jar, and the total value is $90.00. How many one-dollar bills and how many five-dollar bills are in the tip jar?

30 one-dollar bills and 12 five-dollar bills.

Step-by-step explanation:

Let x represent number of one-dollar bills and y represent number of five-dollar bills.

We have been given that a tip jar contains x one-dollar bills and y five- dollar bills. There are 42 bills in the jar. We can represent this information in an equation as:

We are also told that the total value of all bills is $90.00.  We can represent this information in an equation as:

Upon substituting equation (1) in equation (2), we will get:

Therefore, there are 12 five-dollar bills in the tip jar.

Upon substituting in equation (1), we will get:

Therefore, there are 30 one-dollar bills in the tip jar.

after simplifying it i got: -36.25 as my answer. hope that !