I NEED HELP ON THIS MATH PROBLEM EMERGENCY.

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?

Simplify -4z+2y-y+-18z a.-22z+y b.-14z+2 c.3y+22z d. y +14z

8litres of paint can cover 129.6 m². how much paint is required to paint an area of 243m²?