SOLUTION: The volumes of two spheres are in the ratio 64:27 Find the difference of their surface areas, if the sum of their radii is 7 units?

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Question 253744: The volumes of two spheres are in the ratio 64:27 Find the difference of their surface areas, if the sum of their radii is 7 units?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
r= one radius
R=other radius
v=one volume
V=other volume

volume+of+sphere=4%2F3%2Api%2Ar%5E3
r+R=7
r=7-R and v=4%2F3%2Api%2Ar%5E3 and V=4%2F3%2Api%2A%287-R%29 and v%2FV=64%2F27
r = 4 units
R = 3 units
v+=+%28256+pi%29%2F3, V+=+36+pi
v=268.083 cubic units, V=113.097 cubic units
surface area=4%2Api%2Ar%5E2
4%2Api%2A4%5E2-4%2Api%2A3%5E2 =4%2Api%2A%284%5E2-3%5E2%29=4%2Api%2A%2816-9%29=4%2Api%2A7=28%2Api=87.96 square units