Question

Need help with a quadratic equation. x^2+2x-3=0.

Answer 1

x=1,-3

Answer 2

how did you get that?

Answer 3

I can show you.
Have you learned how to factor quadratics or know the quadratic formula?

Answer 4

http://www.youtube.com/watch?v=N30tN9158Kc&feature=relmfu

Answer 5

http://www.youtube.com/watch?v=eF6zYNzlZKQ&feature=relmfu

Answer 6

I'm just learning how to factor quadratics.

Answer 7

watch the two lectures I posted. you will understand all you need to

Answer 8

factor, then solve the factors.

\[x^2 + 2x - 3 = 0\] factors to (x+3)(x-1)=0

Then you just solve independently x +3 = 0 and x-1 = 0 because if either terms (x+3) or (x-1) = 0 the whole thing equals zero.

Your two answers are then x = -3 and x = 1.

Answer 9

the book I have shows an example that has me getting a square root and solving that way which has me coming up with the square root of 7.

Answer 10

You can ALWAYS use the quadratic formula...

Answer 11

@bryanj, you're method makes more sense to me. Can all "solve by completing the square" problems be solved using the quadratic formula?

Answer 12

you did some calculation error in employing the quadratic formula which involves a square root

Answer 13

yes, ALL quadratics can be solved by quadratic formula. but completing the squares is more elegant in some cases.

Answer 14

Ok, so I have a problem that has the answer -2-3(sq. root symbol on the 3) and -2+3(sq. root symbol on the 3)
the problem is v^2+4v+1=0
Can the quadratic formula be applied the same way or is it set up differently?

Answer 15

quadratic formula can be used in this case, where a = 1, b = 4 and c =1

if you take those values for a b and c and plug them into the quadratic formula you should end up with those answers

Answer 16

yes, the quadratic can be applied in the same way. you already have the roots.

Answer 17

ok I think I'm getting it now...I'll try a few on my own and if I need more help, I'll beb ack to this great site!

Answer 18

good. do that.