What 17/12 as a mixed number a) 7 1/2 b) 7/12 c) 1 5/12 d) 12/7

If 2(a^2+b^2)=(a+b)^2 then, > a+b=0, > ab=0, > a=b, > 2a=b

Math it's appreciated. (picture provided)

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.