Hi ppl I really need help in some exercise!!!

it's about comparison.(what is smaller,bigger...)

1)Nth root seventeen ___ Nth root 6 + Nth root 3

2)Nth root seven + Nth root five ____ Nth root 2 + Nth root twelve

3) x+4= Nth root (inside of it: 3x^2+5x-4)

4) (x^2+3x)^2 -14(x^2 +3x) +40 = 0

5) (x+6/x)^2 -12(x+6/x)+35=0

plz help me!!!!!!! i will be grateful to the one who show mw how i need solve atleast one of those...

p.s

i solve(with your help,thank you!!!) all the exercise except number 3.help plz:]