Which of the following is a radical equation? x+√5=12 x^2=16 3+x√7=13 7√x=14 pleas i just have 20 minutes for answer the question

The answer would be: 7√x=14 
A radical equation is an equation with at least one variable put on a radical form. In this question, there is only one kind of variable which is x. Then, you need to find the equation where x is in the radical form. The radical form can be expressed with square root symbol.The option with √x would be only 7√x=14 

All except for b, because polynomial functions can be quadratic, cubic, witticisms and etc only non negative exponents of negative it is not a polynomial function