Question

What method would you choose to solve the equation 2x^2-7=9? explain why you chose this method.

Answer 1

2.87

Explanation:

2x^2-7=9

2x^2=9+7

2x^2/2=16/2

(square root)x^2=(square root)8

x=2.87

I used this method because I don't know any other method.

Answer 2

Sample Response: I would use the square root property of equality. Because there is no x term, I would just add and divide to get x^2 by itself. Then I would take the square root.

2x^2 - 7 = 9

2x^2 - 7 + 7 = 9 + 7

2x^2 = 16

2x^2/2 = 16/2

x^2 = 8 (square root of 8 would be square root of 4*2 = 2*square root of 2

x = +/- 2*square root of 2