Answer: To pay her bill with the minimum balance to avoid the fee, she needs the total amountof $300+$125.43=$425.43. But she only has $325.54. So, the extra minimum amount she needs to deposit is 425.43-325.54=$99.89.
Hence, the answer is $99.89.
Both a and b are functions. for it to be a function, you can only have 1 y value per x value.
this is not a function because 1 has 2 y values
(1,3)(2,5)(1,4)(3,2)