Question

What method would you choose to solve the equation 2x2 – 7 = 9? Explain why you chose this method.

Answer 1

I would use the square root property of equality. Because there is no x term, I would just add and divide to get x2 by itself. Then I would take the square root.

Answer 2

Since there is a power of 2 and constants, without a variable power of 1, I would use square root method.
Move the 7 to the right and you get 2x^2 = 16
Then divide both sides by 2 and get x^2 = 8
Now take the square root of each side and get x = +-sqrt 8
sqrt 8 can be simplified since 2*4 = 8 and 4 is a perfect square.
Therefore the final answer is x = +-2sqrt2