Question

This equation shows how Rosa's bank account balance is related to the number of raffle tickets she purchases. d = -3.4r + 63.6 The variable r represents the number of raffle tickets she purchases, and the variable d represents the balance of her bank account. How many tickets does Rosa need to buy to get the account balance down to $22.80?

Answer 1

So we know that $r$ is the number of raffle tickets she purchases and $d$ is the balance of her bank account.

We are given the equation $d = -3.4r + 63.6$ and we want to get the $account ~balance$ down to $22.80. So since $d$ represents the account balance just plug in $22.80 for d and solve for r. 

When you do that you should get $r = 12$.

So, Rosa will need to buy 12  tickets to get her account balance down to $22.80.