One side of a regular triangle is 5 units. What is the perimeter of the triangle?

Which of the following expressions is equal to 2x^2+8

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

What are the excluded values? m+5/mn+3m