I linked a picture it's algebra review​

The graph below shows the amount of money left in the school’s desk fund, f, after d desks have been purchased. for each new desk that is purchased, by how much does the amount of money left in the school’s desk fund decrease?

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?

Draw a scaled copy of the circle using a scale factor of 2