Pre-calculus help! (Quadratic equations)

[xnatalie22]

Here is the problem:

2b² + 10b + 5 = 0

Solve by using the quadratic equation by the square root method.


I've tried this problem multiple times and I can't seem to get it.

 

[tkhunny]

What did you get? How did you do it?

 

[xnatalie22]

10 ±

10² - (4) (2) (5) = 0 / 4

10 ±

100 - 40 / 4

I know that's completely wrong. The answer in my textbook is: ±

15 - 5 / 2