does 25+(-4)+(-6) equal 15?

According to Cortana, yes.

We can write 25+(-4)+(-6) as-

  25 - 4 - 6

= 21 - 6

= 15

Thus, 25+(-4)+(-6) equals to 15

25+(-4)+(-6) equal 15

x + (-y) is the same as saying x - y

25 + (-4) is the same as saying 25-4

25-4=21

21 + (-6) is the same as saying 21-6

21-6=15.

Yes, 15 is the answer that you are looking for :)

Yes

=> 2 5 - 4 - 10

=> 25 - 10

=> 15