Respuesta :

irspow
Always look at the prime factorization of the numbers under the radical signs to know what can be moved out from under the radical sign...

√8+3√2+√32  so

√(2*2*2)+3√2+√(2*2*2*2*2)  so upon removing the perfects squares...

2√2+3√2+4√2  which is

(2+3+4)√2

9√2
√8 + 3√2 + √32
√2*4 + 3√2 + √4*8
√2√4 + 3√2 + √4√8
2√2 + 3√2 + 2√8
2√2 + 3√2 + 2√2*4
2√2 + 3√2 + 2√2√4
2√2 + 3√2 + 2(2)√2
2√2 + 3√2 + 4√2
9√2

Therefore the third option is correct.
It's just factoring and adding like terms