Free points plz forgive me for the wrong question(s)

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

Simplify (1/2)4th power a. (1/16) b.(1/8) c.(1/4)

3x + 4y = 5 x- 3y = -7 solve by substitution