To find volume, you do “v=l(w)(h)” so you plug is your constant and variables. So In this case l=2x *w=3x* h=x. Your answer should be 6x^3. Your repeat the steps for the second box with the new variables. And your answer for box number two would be 8x^3. Then you add your answer together to get 14x^3. As for the last question all you do is repeat the same steps, but instead of yawing “x,” you substitute it for 6. Hope this helps.