## anonymous one year ago Solve: x2 + 2x - 1 = 0

1. Nnesha

i'm pretty sure you know how to factor that :-

2. ParthKohli

That can't be factored, honestly.

3. anonymous

i got $-2\pm \sqrt{8}> divided by 2$

4. anonymous

oh wait

5. ParthKohli

Looks alright to me. You can write that as $$-1 \pm \sqrt 2$$

6. Nnesha

factor 8

7. anonymous

square root of 8 is a long decimal

8. anonymous

$x^2+2x=1,add~1 ~\to~both~sides$

9. ParthKohli

$\sqrt 8 = 2 \sqrt 2$

10. Nnesha

$\huge\rm \frac{ -2 \pm \sqrt{4 \times 2}}{ 2}$ yep right that's why you to factor 8 4 times 2 =8 now take square root of 4

11. Nnesha

have**

12. anonymous

thats what i got, but what next?

13. ParthKohli

Then you've solved it.

14. anonymous

1 + √2 and -1 - √2 -1 + √2 and -1 - √2 -1 + √3 and -1 + √2 -1 - √2 and 1 + √2

15. Nnesha

$\huge\rm \frac{ -2 \pm 2\sqrt{ \times 2}}{ 2}$ 2 is common so take it out

16. anonymous

oh

17. anonymous

so,..|dw:1433904972339:dw|

18. anonymous

i will fan all of u if you help me with 3 questions

19. anonymous

is that it?

20. anonymous

$x^2+2x+1=2,(x+1)^2=2,x+1=\pm \sqrt{2}$ $x=-1\pm \sqrt{2}$

21. anonymous

so i am right

22. Nnesha

$\large\rm \frac{ \cancel 2(-1 \pm \sqrt{ 2})}{ \cancel2}$ yes you got it right!

23. triciaal

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