2/5, the formula is art over swimming, 16/40, then simplify 2/5
The answer is D. Subtract 9y from both sides of the equation.
From V= 4/3*pi*r^3
<span>dV/dt = 4pi(r^2)dr/dt </span>
<span>so when dV/dt=30 and r = 19 </span>
<span>30 = 4pi(361)dr/dt </span>
<span>dr/dt = 30/[4pi(361)] </span>
<span>now in </span>
<span>A = 4pir^2 </span>
<span>dA/dt = 8pi(r)dr/dt </span>
<span>= 8pi(19)*30/[4pi(361)] </span>
<span>= you finish it.</span>
<span>HOPE THIS HELPS.
</span>
Answer:
C 7 times 5 plus 7 times 4 is the answer
