To the nearest tenth of a square inch, how much surface area is added to a spherical balloon whose radius grows from 10 to 20 inches long?

Question

espex · Answer

You know that the surface area of a sphere is calculated using: $$4\pi r^2$$

anonymous · Answer

Yes. I guess i didnt type my actual question out. after using that formula for the radius being 10 and then 20 do i subtract?

espex · Answer

Yes, because you have an initial value and a "new" value. You are interested in how much it has changed.

mathstudent55 · Answer

Using the formula eSpeX gave you, find the surface area for the baloon with 20 inch radius and with 10 inch radius. Then subtract. The difference is how much was added.

anonymous · Answer

Thank you both eSpex and mathstudent 55!! Y

anonymous · Answer

Yall are very helpful!