expressions equal to 12n - 8, dont necessarily need help but it would be cool if I received some answers

What could explain what happened when the time was equal to 120 minutes

In which form is the following function written? y = - 2(x – 3)(x + 5)

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