Question 996961
if x and y are two positive real numbers such that 25x square  + 49y s quare equal to 841 and xy equal to 12 then find the value of 125x cube  + 343y cube
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841 = 400 + 441 = 25*4^2 + 49*3^2
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x = 4, y = 3
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125*4^3 + 343*3^3 = 8000 + 9261
= 17261