The floor of a canyon has an elevation of -6.5 feet erosion causes the elevation to change by -0.25 feet per year. how many years will it take for the canyon floor to have an elevation of -20 feet.

Arecipe uses 2 cups of sugar to make 32 brownies. how many cups of sugar are needed to make 72 brownies?

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

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. after tax the total is 45.99. what percentage of the subtotal is the total?