Halp me plez

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?

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. after tax the total is 45.99. what percentage of the subtotal is the total?

What is the measure of angle x? 37° 82° x°