SOLUTION: If a:b :: c:d, show that: ac : bd = (a^2+c^2):(b^2+d^2)

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Question 389359: If a:b :: c:d, show that:
ac : bd = (a^2+c^2):(b^2+d^2)
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
. The last equality in the chain is true because it was shown before that a%5E2%2Fb%5E2+=+c%5E2%2Fd%5E2+=+%28a%5E2+%2B+c%5E2%29%2F%28b%5E2+%2B+d%5E2%29 for the same given a:b :: c:d.