Ineed quickly this is timed, im not very good with !

Area of rectangle: b*h

12*5=60

10*5=50

(60*4)+(50*4)=440

The total surface area of the visible sides of the boxes would be 440 square inches.

Hope this helps!

That would be 2 * 10*20 + 2 * 12*20 + 10*12

= 400 + 480 + 120

= 800 in^2

i think it will be zero as slope has a formula of difference between initial and final distance divided by itz time interval