Hello! Good evening gurus in the house. Please I need a little help figuring out this quantitative reasoning

So far I've been able to figure out part of it but can't figure out the last part

From the first example:

9 + 25 = 34
34 - 25 = 9
34 - 9 = 25

I can't figure out how to get the 4

Same for the second and third example can't figure out to get the 2 and 0.

Thanks in advance.

Modified

I've been able to figure it out

9- √ 25 =
9 - 5 =4

4 - √ 2=
4 - 2 =2

25 - √ 625=
25 - 25 =0

you get the point now