Answer:
Okay so I am assuming you mean the third part?
Explanation:
Pretty simple. So you see that the varible x^2 does not have a number in front of it, so there is no extra dividing.
A formula for a perfect square is (x^2)+2xy+y^2
Take 10 and divide it by 2.
10/2=5
You have Y. Finding the third part is squaring Y.
5^2=25
Therefore, the third part of the perfect square is 25. If you want to find Y, look at the stuff above.