X^y + x^y = 20 then find x^y - y^x​

And employee salary increased by $4500 which represents a 15% raise what is the rate of the increase

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

Is a square always, sometimes, or never a parallelogram