First, let's break down the given expression:
cos(25) cos(15) + sin(25) sin(15) / cos(10)

Using trigonometric identities:
cos(a) cos(b) = 0.5(cos(a-b) + cos(a+b))
sin(a) sin(b) = 0.5(cos(a-b) - cos(a+b))

Let's simplify further:
0.5[cos(25-15) + cos(25+15)] + 0.5[cos(25-15) - cos(25+15)] / cos(10)
= 0.5[cos(10) + cos(40)] + 0.5[cos(10) - cos(40)] / cos(10)
= cos(10)/2 + cos(40)/2 + cos(10)/2 - cos(40)/2 / cos(10)
= cos(10)

Therefore, the final simplification of the given expression is cos(10).