2x^2+8x+3=0?? complete the square on. leave in the from a(x+b)^2+c.

Question

anonymous · Answer

I am stuck on 2[(x+2)^2-4+2/3]=0

jamesj · Answer

Because you have a 2 on the outside of the square brackets, and we're trying to get this in the form:
a(x+b)^2+c

anonymous · Answer

I don't understand, sorry.

anonymous · Answer

But If I have to distribute the 2, should we also multiply the (x+2)^2 by 2 as well?

anonymous · Answer

you did you multiply 2(x+2)^2 by 2??

anonymous · Answer

it just stayed the same throughout.

jamesj · Answer

x^2 + 4x + 3/2 = x^2 + 4x + 4 - 4 + 3/2
                          = (x +2)^2          -4 + 3/2, because (x+2)^2 = x^2 + 4x + 4

Now does it make sense?

jamesj · Answer

Given what I've written above, it follows that
2[ x^2 + 4x + 3/2 ]  = 2[ (x+2)^2 + (-4+3/2) ]
that is, line A gives line B

anonymous · Answer

I am going to play around with it. thank you for your help.

jamesj · Answer

ok