4+5+9 =30
9+6+16 =43
16+7+25=58
25+17+36=?

Obviously the '+' in the left side does not indicate addition but a way to
derive the right side from the 3 terms on the left side.

You will notice that the 1st and 3rd terms on the left side are perfect 
squares and that gives a clue. Rewrite the equations as

2^2 + 5 + 3^2 = 30, which is 2 + 5^2 + 3
3^2 + 6 + 4^2 = 43, which is 3 + 6^2 + 4
4^2 + 7 + 5^2 = 58, which is 4 + 7^2 + 5

The right side is derived as sqrt of 1st term + square of 2nd term + sqrt of 
3rd term.

So 25 + 17 + 36 is sqrt(25) + square(17) + sqrt(36) = 5 + 289 + 6 = 

:)