How do i know which points to use when finding the line of best fit

Select the sequences that are geometric.

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax

Ineed someone to me answer my question i have to have this done and knocked out