Explanation:
It is given that,
The surface area of a spherical balloon with radius r meters is given by :
[tex]s(r)=4\pi r^2[/tex]
The radius P(t) (in meters) after t seconds is given by, P(t) = 73 t.
We need to write the surface area N(t) (in square meters) of the balloon after t seconds.
[tex]s(r)=4\pi [P(t)]^2[/tex]
[tex]s(r)=4\pi [73t]^2[/tex]
[tex]s(r)=21316\pi t^2[/tex]
So, the surface area of the balloon is [tex]21316\pi t^2[/tex]. Hence, this is the required solution.
