Answer:
The surface area of the balloon is
![S(t) = (100)/(49) \pi t^8](https://img.qammunity.org/2022/formulas/mathematics/college/92brvzygn19z56k44wlxdn8ot823zzngvo.png)
Explanation:
Given;
S(r) = 4πr²
where;
S is the surface area of the balloon
r is the radius of the surface
The radius of the balloon at time "t" is given as;
![r(t)= (5)/(7) t^4 \ \ \ t\geq 0](https://img.qammunity.org/2022/formulas/mathematics/college/3zx3xnlplopfxq0zz5d6tlc5gp9bgsphur.png)
The surface area of the balloon as a function of time "t" is calculated as;
![S(t) = 4\pi ((5)/(7) t^4)^2\\\\S(t) = 4\pi ((25)/(49) t^8)\\\\S(t) = (100)/(49) \pi t^8](https://img.qammunity.org/2022/formulas/mathematics/college/f28vju00912v7ftfcp5pkjsiqxdptyxmma.png)