By definition, we have
So, we have to solve two different equations, depending of the possible range for the variable. We have to remember about these ranges when we decide to accept or discard the solutions:
Suppose that 
In this case, the absolute value doesn't do anything: the equation is
We are supposing 
, so we can accept this solution.
Now, suppose that 
. Now the sign of the expression is flipped by the absolute value, and the equation becomes
Again, the solution is coherent with the assumption, so we can accept this value as well.
The discriminant is the part of the quadratic formula underneath the square root symbol: b²-4ac. The discriminant tells us whether there are two solutions, one solution, or no solutions.
I’m sorry I can’t help ypu
Answer: To find the finance charge you multiply the balance times 0.23 / 12 .
To find the interest charge to an account, you have to multiply the balance by the percent rate (APR).
The problem in this case is that interest is charged monthly, but the rate is yearly.
To fix this problem, just divide the rate by 12.
0.23 / 12
