What is the answer?

What is the anwers for 9+2x=5x-3-x

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

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x