Question

Anyone know this?? Thanks

Answer 1

9514 1404 393

Answer:

x = 4

Explanation:

The figure is a rhombus when the sides are the same length.

21 -x = 2x +9

12 = 3x . . . . . . . . add x-9 to both sides

4 = x . . . . . . . . . . divide by 3