Quadratic equation 2x^2+10x+2=0

[carrotjuice]

Hello there. I'm having some trouble with this. The problem is 2x^2+10x+2=0 and the answers to choose from are:
a. -5±?21/2
b. -5±?29/2
c. -5±?21/4
d. -10±?21/2

I don't really understand though. I keep getting -10±?84/4 and if I simplify it by 2, the ?84 turns into ?42... I know I'm doing this wrong, but I don't get it... Any help would be appreciated.

 

[Deleted member 4993]

Hello there. I'm having some trouble with this. The problem is 2x^2+10x+2=0 and the answers to choose from are:
a. -5±?21/2
b. -5±?29/2
c. -5±?21/4
d. -10±?21/2

I don't really understand though. I keep getting -10±?84/4 and if I simplify it by 2,

?(84) = ?(4*21) = 2 * ?(21)

so

(?84)/4 = ?(21)/2

the ?84 turns into ?42... I know I'm doing this wrong, but I don't get it... Any help would be appreciated.

 

[carrotjuice]

Hello there. I'm having some trouble with this. The problem is 2x^2+10x+2=0 and the answers to choose from are:
a. -5±?21/2
b. -5±?29/2
c. -5±?21/4
d. -10±?21/2

I don't really understand though. I keep getting -10±?84/4 and if I simplify it by 2,

?(84) = ?(4*21) = 2 * ?(21)

so

(?84)/4 = ?(21)/2

the ?84 turns into ?42... I know I'm doing this wrong, but I don't get it... Any help would be appreciated.

So would it be letter d or a, but I'm not sure if the -10 factors in as well? Sorry, I'm really confused.

 

[Deleted member 4993]

First factor out 2 to convert your equation to:

\(\displaystyle x^2 \, \, + \, 5x \, + 1 \, = \, 0\)

This will make things simpler.