I need help with this please. Can someone help me?

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)

Arestaurant charges $100 to rent its banquet room for an event. it also charges $15 to serve dinner to each guest. write an equation for the total cost of the banquet room in terms of the number of guests. deine your variables. what is the total cost of the banquet room for 20 guests?

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?