Question

TEOREMA DE TALES x/y =10/5 xy=21

Answer 1

x = 10 ==> x = 2y
y     5

xy = 21
====================
2y.y = 21
  y² = 21
          2
               ____
  y = +/-V21/2
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                                  _____
x = 2y ==> x = +/- 2V21/2