Solve the equation x^2 -100 = 0

On the april 3 billing date, michaelle chappell had a balance due of $ 1495.39 on her credit card. from april 3 through may 2, michaelle charged an additional $ 305.34 and made a payment of $ 800.a) find the finance charge on may 3, using the previous balance method. assume that the interest rate is 1.8 % per month.b) find the new balance on may 3.

I’m confused on how to work the pie charts

The quotient of 15 and a number is 1 over 3 written as an equation