Respuesta :

9514 1404 393

Answer:

  x = -9

Step-by-step explanation:

Segment NL is twice the length of midsegment WV.

  2WV = NL

  2(x+15) = x+21

  2x +30 = x +21 . . . . simplify

  x = -9 . . . . . . . . . . . . add -30-x

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Additional comment

This value of x means the other segments are ...

  MN = 12

  WV = 6

  NL = 12