Which of the following is a radical equation?

Answer:
D) [tex]7\sqrt{x} = 14[/tex]
Step-by-step explanation:
If x is under a radical symbol, then it is called radical equation.
For example, [tex]\sqrt{x} = 2[/tex]
[tex]\sqrt{x-2} = 5[/tex]
From the given equations, we have to find in which equation x under radical.
x + [tex]\sqrt{5} = 12[/tex], here x is not under radical.
[tex]x^{2} = 16[/tex], here also x is not under radical.
3 + x√7 =13, here x is not under radical
7[tex]\sqrt{x} = 14[/tex]
Here x is under the radical symbol.
Therefore, the answer is [tex]7\sqrt{x} = 14[/tex]