Answer:
Which part of the diagram shows the quantity x? What about 4? What about 17?
b. You must add the boxes together to show that it is 17.
How does the diagram show that x+4 has the same value as 17?
c. The value of the x+4 and 17 is the same because according to the diagram the quantity of x+4 is showing 17, so they have the same value.