There are two different ways to tackle this problem:

1. Factoring and using the principle of zero factors.
2. Using the principle of square roots.

First way:



Factor the left side as a difference of squares





Since the product of (2x-5) and (2x+5) equals zero,
one of them must equal to 0.

; 
  ;    

Divide both sides by 2

   ;    

-----------------------------------------------------------

Second way: Using the principle of square roots.



Add 25 to both sides:



Divide both sides by 4:







Use the principle of square roots:





Which is easier?

Edwin