Answer:
7z + 5 + 6z - 9 (Add 7z and 6z, subtract 9 from 5)
<em>13z - 4 </em>(Can't be simplified further)
Simply multiply the baby's original weight, which is 7.25 lbs, by 2.5
7.25lbs x 2.5 = 18.125 lbs
The baby weighted 18.125 pounds at the end of 8 months.
Hope this helps and May the Force Be With You!
-Jabba
