How do i convert 9 into a fraction and into a percent

What is the size of the matrix resulting from

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

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"