Which of the following is a radical equation? a. x sqrt 3=13b. x+sqrt3=13 c. sqrtx+3=13d. x+3 =sqrt 13

The answer for this question is C. 
First subtract the 3 from both sides to get : sqrt(x) = 10
Then square both sides to get: x = 100
The other equations can't simply proving that they cannot be radical equations
Hope this helps :)