Respuesta :

Answer:

  A.  2x² +12x

Step-by-step explanation:

If the mobile is balanced, the weights at each level are the same. Each of those in the lowest tier will be equivalent to 3x, for a total of ...

  4×3x = 12x

Each of those in the top tier shown will be equivalent to x², for a total of ...

  2×x² = 2x²

Then the sum of all parts will be ...

  top tier + bottom tier = 2x² +12x