SOLUTION: How do you complete the square for this question:y=2x^2+4x-2 ? I got y = 2(x+1)^2 - 2 but the answer says its y = 2(x+1)^2 - 4. Can someone please tell me where they got the -4 fr

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: How do you complete the square for this question:y=2x^2+4x-2 ? I got y = 2(x+1)^2 - 2 but the answer says its y = 2(x+1)^2 - 4. Can someone please tell me where they got the -4 fr      Log On


   

Question 1115016: How do you complete the square for this question:y=2x^2+4x-2 ?
I got y = 2(x+1)^2 - 2 but the answer says its y = 2(x+1)^2 - 4. Can someone please tell me where they got the -4 from?
Thanks
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
2x%5E2%2B4x-2
2%28x%5E2%2B2x-1%29
Term to complete the square is %282%2F2%29%5E2=1, which should be added and subtracted inside the parentheses.
2%28x%5E2%2B2x%2B1-1-1%29
2%28x%5E2%2B2x%2B1-2%29
2%28%28x%2B1%29%5E2-2%29

Remultiply to distribute the factor 2.
2%28x%2B1%29%5E2-4

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
For those who want to learn completing the square, there is the lesson in this site
    - HOW TO complete the square - Learning by examples


Read it and become an expert in the area.