Mr. Tough can grade the final exams in 12 hours. His assistant, Ms. Nice, can grade the same exams in 15 hours. what fraction of the exams can mr tough and ms nice grade in 1 hour if they work together

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?

Maryann’s friends loved her bulletin board, and 4 of them asked her to make one for their homes. she offered to make each of her friends a replica of her bulletin board that measures 2 meters by 3 meters. how many kilograms of burlap should maryann collect to complete the bulletin boards for her friends? maryann should collect kg of burlap.