For the answer to the question above, I'll show my solution for the answer below.
Area A = pi r^2
<span>The rate of change of area = d A/ d t = 2 pi r d r/d t </span>
<span>r= 2t, d r = 2 d t </span>
<span>This gives </span>
<span>d A/ d t = 2 pi 2t 2 d t = 8 pi t dt </span>
<span>Integrate it </span>
<span>A= 4 pi t^2. </span>
<span>After t=5, the area will be 100* 3.14 square= 314 square units.</span>
Oldest = 2x
Middle = x + 5
Youngest = x
2x + x + 5 + x = 57
combine like terms
4x + 5 = 57
subtract 5 from both sides
4x = 52
divide both sides by 4 to isolate x
x = 13
Oldest = 2x = 2(13) = 26
Middle = x + 5 = 13 + 5 = 18
Youngest = x = 13
Daaaaaaaaaammmmm that’s hard
