Can someone explain and help me solve this?

Question

2x^(1/2)-9x^(1/4)+4

Answer 1

Let        q = x^1/4

            q² = x^1/2

                    

 

The new expression becomes

 

2q² - 9q + 4

 

 

Now we can factor.

 

(2q - 1)(q - 4)

 

 

Finally, we substitute the value of q for x.

 

(2x^1/4 - 1)(x^1/4 - 4)