Sqrt x^2 + 20 = 3 sqrt x #solve the equations

Question

Sqrt x^2 + 20 = 3 sqrt x #solve the equations

Answer 1

My assumption is that equation is :

 

    (x² +20)^1/2   =  3 z^1/2

 

 The first step is to square both sides:

 

    x² + 20  =  9 x    Rearrange this as"

 

  x²  - 9 x +20 = 0   The left side factors

 

   (x-5) (x -4)  = 0   So the solutions are 

 

    x = 5       and   x = 4

 

  These can be checked by substitution into the original equation