Which of the following uses a variable to represent a person, place, or thing that is unknown A. apartment 12A B. a C-sharp on the piano C. Mr. X D. a B+ grade​

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

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?

What is the value of x? enter your answer in the box.