Respuesta :

 1.  As M is the midsegment  JM / JK = 1/2 

By similar triangles  JM/JK = 1/2 = x / 12

2x = 12  so x = 6 answer


2.    By the same reasoning as above

  x / (x + 9 )  =  8.5 / 17  = 1/2
2x = x + 9
x = 9  

Answer x = 9