SOLUTION: can you please help me to solve this equation, 4x^2-25=0

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Question 1062463: can you please help me to solve this equation, 4x^2-25=0
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

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:

4x%5E2-25%22%22=%22%220

Factor the left side as a difference of squares

%282x%29%5E2-5%5E2%22%22=%22%220

%282x-5%29%282x%2B5%29%22%22=%22%220

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

2x-5%22%22=%22%220; 2x%2B5%22%22=%22%220
  2x%22%22=%22%225;    2x%22%22=%22%22-5

Divide both sides by 2

   x%22%22=%22%225%2F2;    x%22%22=%22%22-5%2F2

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

Second way: Using the principle of square roots.

4x%5E2-25%22%22=%22%220

Add 25 to both sides:

4x%5E2%22%22=%22%2225

Divide both sides by 4:

4x%5E2%2F4%22%22=%22%2225%2F4

cross%284%29x%5E2%2Fcross%284%29%22%22=%22%2225%2F4

x%5E2%22%22=%22%2225%2F4

Use the principle of square roots:

x%22%22=%22%22%22%22+%2B-+sqrt%2825%2F4%29

x%22%22=%22%22%22%22+%2B-+5%2F2%29

Which is easier?

Edwin