Get n to one side
-1/5=-2/5n
divide both sides by -2/5
n=1/2
R(t) = 4t
A(r) = π(r^2)
a) A(t) = A[r(t)] = π[r(t)]^2 = π[4t]^2 = 16π(t^2)
b) t = 4,
A(4) = 16*3.14*(16)^2 = 12,861.44
Answer:
b times l times w........
By scientific notation I am assuming you mean standard form, as that is used primarily in scientific calculations. The answer in standard form would be

I hope this helps!