i need help on solving. it looks very confusing to me and seems so hard any help would be appreciated

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

You buy five cds at a sale for $5.95 each. write an expression for the total cost of the cds.then use the distributive property and mental math to evaluate the expression.

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?