If 100% of a number is 200, what is 90% of the number?

Which equation represents the partial sum of the geometric series?

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?

An internet company charges $8.95 per month for the first 3 months that it hosts your web site. then the company charges $11.95 per month for web hosting. how much money, in dollars, will the company charge for 8 months of web hosting?